I've had one for a long time now (got it at the kickstarter campaign). It is the basic T-shirt model (Bradley).
It fits great, nice and light and repels liquids like magic. It is a very nice shirt to wear in temperate whether or when I am not active (explained why below).
I did try to wear it for a week without washing (during the autumn) and it had no foul smells according to my wife, though it did develop that 'yucky' feeling that any other shirt develops without washing.
The main thing that bothers me with the shirt, and the reason I don't wear it often, is actually related to how well it repels liquids. I am a very sweaty guy. I sweat easily and a lot. What I noticed was that wearing this shirt feels very 'yucky' on my back. Usually when I sweat, a regular shirt absorbs the sweat and then gets dried by the wind, which is why I have lots of quick-dry, moisture-wicking shirts. With the Ably shirt it didn't absorb any of my sweat and I could feel my back really wet. Basically, think of the videos you see of this shirt: when you pour water over it, it just rolls off. It really does work this way. But when the water comes from inside the shirt (in the form of sweat) and it rolls off, it really just means that your back feels drops of water over it. It is even worse when I tried hiking with a light backpack.
It is a great buy if you either don't sweat a lot, or if you don't intend on using it in active settings. I would definitely buy some of the newer designs like the dress-shirts as I am unlikely to wear them in situations I would sweat too much. The T-shirt I have, and which I wear as a daily shirt, I am only wearing when the weather is cool and when I am not exercising/hiking.
As for washing: I have had it for a while now and I only washed it by hand in cool water with tiny amounts of soap, air dried. So far no significant stretching and no change in the water-repelling qualities. Still feels great to wear.
If you are in the market for a moisture-repelling shirt, I do recommend trying it with the caveat I mentioned regarding sweat.
Hope it helps.