I have had 2 keep ups and was contemplating whether to get another for the reasons I will describe below. My first 2 cups were the plastic ones and were the first if not, earlier versions of this one sold here. I liked the concept of the cup and found this glass version of it. I was originally contented with a glass version to address tea and coffee stains with its plastic cousin but I found much more.The designs of keepcups are the same regardless of whether it is made of plastic or glass. What I describe will apply to both the models:1. The holder ring is now thicker and does not have labels to indicate type of coffee. Really, that was pointless , which barista is going to risk marking on the cup and hopefully not with a non-erasable marker, to incur the wrath of its customer who decides something else at the next trip?2. The lid now has a lip which makes it easier to open. Inside the little lid, there is also a seamless rubber insert which provides a better deal and prevents leakage that the previous models had.3. Drinking hole. Now slightly bigger and they got rid of the little weir on the other side that just caused a buildup of coffee stains.4. The plastic thing to close the drink hole ( green tongue I call it) now comes with a locking system for removal that actuall goes through the lid to the other side. The older version had it pressed into a circle on the top side and after a series of pulling and pressing for washing, that didn't seal he drink hole very well pretty early on. Unfortunately, the closure of the drink hole is still a loose cover and not spill proof or airtight. I use this at work and have it upright all the time so this doesnt perturb me.Do note though this is more a to-go cup than a travel mug. The design intent is to have a reusable cup that isbboth recyclable and meets standard cup sizes at coffee shops so it does not keep the contents warm like a thermos.I am very satisfied with this KeepCup. It is beautiful. Thoughtful design has gone into this product (more on this later).From the pictures you can't really tell the size of the cup. It was larger than I expected and very well made. The plastics are top quality. It went into my dishwasher and came out shiny, clean and perfect. I am always afraid of plastics in the dishwasher because I have heard horror stories about items that are deformed under the high water temperatures. Not the case here.THIS IS PERHAPS THE BEST FEATURE ABOUT THIS PRODUCT AND IT IS NOT MENTIONED ANYWHERE: About the thoughtful design... You cannot tell from the pictures but the mouth hole or whatever you call the opening on the lid from where you drink your coffee/tea is PERFECT. It is so comfortable to drink from it. There are a lot of travel mugs which have poorly designed openings, some even resemble a coin slot which makes a mess whenever you drink from them. Not the case here! The opening on the lid has the shape of a triangle with rounded corners, so your lips make a perfect seal when drinking (go ahead, pretend you are drinking from a travel mug and you will realize the rounded triangle shape is what you need!) This should be of primary concern to anyone who designs a travel mug! Your lips must fit comfortably in the lid opening.THERE IS ONLY ONE PROBLEM: This travel mug doesn't really provide much thermal insulation. Your drink will stay hot maybe 15 to 20 minutes and that's it. I commute for about 15 minutes in the mornings and by the time I reached work, the contents were only warm. Give it 10 more minutes and its more on the cold side. There is no double wall insulation, so this is pretty much a glass with a silicone band and a VERY well designed lid.Mine smashed because I dropped it on the concrete floor at work.Probably the 3rd or 4th time I dropped it. I've had it 3 weeks. I love it so much I'm going to try it again. I've been drinking many different teas at work as I drive from one workplace to another. I would not be able to enjoy the flavor if the cup itself was plastic. Sometimes I take the lid off to drink straight from the glass. Though the lid adds a very slight flavor, I usually don't mind or notice it. Much better than silicone lids which for me simply never lose their silicone taste. Comes apart very easily, I usually just rinse all the pieces especially when switching from coffee to tea. If coffee dried on the inside of the glass, I used some soap.. I have washed all the pieces twice in the dishwasher so far. A teabag string does not seem to make the lid leak from the rim. The very slow leak coming from the center of the lid where the plug attaches is manageable. I don't usually have problems with it shoved into my backpack's water bottle pocket.This is a great cup for taking coffee on the go. I use a moka pot at home to make cappuccinos/lattes and bring them to work in this. Its true that its not as insulated as a thermos, but I didn't find the coffee to instantly cool down in it either (I do have a short commute). For me it came down to having a nice cup to drink out of that was the right size for an espresso-based drink. I didn't want to buy a giant thermos or bottle that would be hard to pour into and ridiculous to drink out of.The lid seals nicely, and the drink opening is a nice enough size that you don't feel like you're sipping through a straw. As some others have mentioned, I could taste the plastic of the lid a bit at first, although after about a week it seems to have gone away.I would definitely recommend getting the 12 oz size over the 8 oz - I was on the fence, but even the 12oz is certainly not a large cup - the smaller size would really limit you to strictly the smallest drinks with no room to spare. I don't quite fill mine even when adding milk and foam, but its nice to have a little room to spare.I work for a company who prides itself on being sustainable, so used to get scowls whenever I walked back in with my post-lunch coffee in a paper cup. Thus began my hunt for a good reusable cup (I have had plenty of others, generally they have been the larger types you get given as promotional items, and they all had their flaws).I seriously considered both the double-walled cups available from other sellers/manufacturers on Amazon, as well as the plastic KeepCups. Here's why I chose this one - and why I love it:KeepCup seem to know their customers well, and have chosen a design that just works. It's the right size so when you give it to someone at a coffee shop, they don't baulk at it's height (my other ones were always too tall). The lid sits well and seals well. The insulation band insulates, and the coffee doesn't cool too fast or slow (the latter can lead to bitterness, I find).It's glass, not plastic or metal. I have had coffee flasks with both and have found the taste of the coffee changes slightly (usually for the worse - particularly with plastic), so knew I wanted glass.It's not _too_ expensive so I didn't feel the cost was prohibitive. Plus I love the colour (I went for Fig, but there's plenty of choices and you can create your own on the official store site).I went for 12 oz, as I worked out this would be the appropriate size for most coffees. I have (90% of the time at least!) an Americano, and it's the perfect size for that.I went for the silicon band rather than cork as apparently the cork one shouldn't go in the dishwasher. Not really a problem for me as I always hand wash mine, but I wanted to ensure that if the office cleaners ever got hold of it and put it in the dishwasher, it would survive! I have no problem holding & carrying mine even when it's full of freshly brewed coffee.I don't think there's much more I can say that hasn't already been said. If you're thinking of getting one, I can highly recommend it!I love the design and feel of this cup, but I have to admit that after cleaning thoroughly I have noticed the lid smells strongly of coffee. I used the cup to drink both tea and coffee; I find when I drink the tea, I get a faint taste of the coffee if I am drinking with the lid on.I loooove this cup. It doesn’t leak when I drink cappuccino or latte, but if I make coffee myself (watery) then it leaks and I have to keep a napkin under the lid. Such a shame. Probably will buy a replacement lid. However it’s £7 with postage..I use this as a normal glass at home and its good for out and about as well. Not entirely leak-proof and sometimes the lid takes a bit of pushing to get it on but at least it is secure. Doesnt taste weird which is aways a positive. Not too heavy but if like me, you have a heavy-ish handbag already, this is a noticeable increase in weight but if you are holding it, its almost nothing. Im a fanHandy cup that's great at stopping spillages whilst going upstairs etc. I also filled it with water and tipped it upside down and it didn't seem to leak. With it being glass I'm not sure I'd like to walk around outside or commute on public transport with it but for indoors it's great. Not insulated but the lid helps keep the heat in so your drinks stays warm a bit longer.