Good, for a while
I bought this cup four months ago. It worked great, the coffee stayed hot, and only occasionally would it leak. But the lid would get stuck from time to time, until it broke in half, making the cup unusable.

Great if you want a thermos
On the plus side, this keeps liquids hotter than anything I've ever used. If closed tightly it really does not leak.
But closing it isn't the problem. It can form a pretty tight seal and to grasp and turn the very smooth ridge on the top can require dexterity, especially if your hand or the top is wet.
Also, the lip is not flat, but curves up on either side, presumably to facilitate drinking without spilling. But it means you have to be very careful if you want to put anything on top, like an AeroPress. Because it is taller than wide, "mug" and press can tip over if you, as I am, are not exactly awake first thing in the morning. The handle sticks out quite a bit. This is probably fine for a car. But you really can't pack this as easily as you could if there were no handle.

Great mug - you realy get what you pay for!!
We purchased two of these mugs for use in our motorhome. We were tired of all the cheap mugs we had bought or had been given over the years as promotions, and decided to spend the money on what we hoped would be top-quality mugs. I'm happy to say that they were definitely worth the investment!

We were a little unsure of them before we ordered because we really didn't understand how the lids worked. However, they're pretty simple and straightforward. They are a simple screw-in cap that when screwed completely in makes the mug act like a traditional thermos, keeping coffee hot for 4 hours or more, and making the mug spillproof. Turning the cap one quarter to one half turn opens the mug for drinking, and even when open we've found that it keeps the coffee hot for 2-3 hours without any problem.

The mugs are very comfortable to drink from. They fit into any cupholders, have a comfortable feel in your hand, and look pretty cool as well! They also come with a carabiner that lets you clip the mug to packs, etc. for carrying. The quality stainless steel interior is easy to clean and doesn't absorb odors when swithing between coffee and tea or other beverages.

If you want a quality travel mug that does exactly what it claims to do, you don't need to look any further than this top-quality mug. You really do get what you pay for!

Great Travel Mug
I decided to purchase this item based on the good reviews I read on this site. I was not disappointed. I do a lot of driving for my job, and a good travel mug is important. This mug holds the perfect amount of coffee, and keeps it hot for hours. I can make the coffee in the morning, and finish it for lunch. It fits easily into the cup holder, and I don't need to worry about spills in the car. It is comfortable to hold and drink out of. My only criticism, and this is very minor, is that if you turn the cap too far, it is difficult to open again. But, if you are mindful of this, it's not a problem.

Great heat retention, excellent against spills!
I got this as a gift for someone in our office that is notoriously bad at spilling coffee all over his cube/self. He raves (and not just to be polite) about it.

His comments:
Contours are excellent and comfortable.
Heat retention is spectacular (left outside in cool weather for hours, and still hot enough to almost burn his mouth).
The top is not metal, so no nasty teeth-clinking.
Can open the top to varying degrees to control the liquid dispension (which also helps cut down on spillage if it IS spilled while unlocked.
Openings on BOTH sides, so easier to drink from.
Does NOT spill at all when the lid is locked.
Fits perfectly in car cup holders.

So far, he hasn't spilled it at all, but we have a betting pool in place for when he does (although now, I think the pool will get much bigger).

I would highly recommend this for coffee drinkers.