Not a bad brewer, but the supplied tumbler will make you wish you bought something else.
Positive Product Points
Small design a plus for brewing single cups. Bright, easy to read digital display.
Negative Product Points
Water compartment is too small ... should be larger or more round; When making multiple cups need to press "On" button twice; Must use only the tumbler provided or brewer won't work.
Tumbler has numerous issues: Top heavy, which makes it easy to tip (done this numerous times), screw-top cap seal can leak if not properly set (many a shirt stained); using screw top with steaming coffee causes leaks around the seal and vent holes (due to built up steam); When using screw-top with full cup, no syphon hole which causes gurgle when drinking.
Overall, when you get past the nuances of this brewer, it makes a good cup of coffee. The mail issue I had with the brewer was that you needed to use the supplied tumbler. And the tumbler had to be correctly positioned or no coffee. I eventually disabled this by removing the spring mechanism. But beware ... you need to make sure you have a tumbler in the machine when you hit the "On" button.
My only other real gripe about the brewer is the water hole. It is rectangular in shape and if you are not careful, you will spill water. This can be very annoying, especially since you have had your morning coffee yet.
Although this isn't a tumbler review, I have will comment on this because the machine (if you do not alter it as I did) requires you to use it. This has to be the worse piece of engineering I've ever seen. First and foremost, it is very top heavy. It is very easy to tip over and has happened to me many times. I use this tumbler for commuting and it constant wiggles around in my cup holder when full. Even empty, it is unstable.
Second, there is a rubber gasket that seals the screw-top to the cup. The issue here is that the gasket is not fixed. If the gasket is accidentally moved when you wash the cup, or sometimes when you screw the top to the cup when hot, the gasket doesn't always seal. This results in a leak at the edge just below where you take a sip. I can't count how many times I've showed up at work with coffee stains on my shirt or lap.
Third, the screw-top has a lid that you can close so as not to spill coffee while carrying the tumbler. If you close this lid right after you brew the coffee, steam gets built up inside and eventually causes leaks around the gasket and in the two vents holes in the lid.
Fourth, when drinking from a full tumbler using the lid, there is no hole for releasing the pressure, so basically you get a gurgled response. This and previous item could be easily fix with a small siphon hole on the lid opposite of the drink hole.
One last tumbler gripe. If you screw the lid on while the cup is cold prior to brewing the coffee, then brew the coffee, the cup's metal expands due to the change in temperature and leaks between the cup and screw-top. If you don't remember this, you get a stained shirt. If you do and tighten the lid, then when it cools down it is very hard to unscrew the lid.
This machine does make a good tumbler of coffee, but it makes this coffee geek think twice before every sip. As a result, I'm shopping for a new machine .