It was also pretty easy to setup, however the instructions that came with it weren't that detailed. I'm a tetchy sort though so I didn't have too many problems.
First thing I noticed though was the back light...or back not-so-light as its better known as...very dim in fact, even in the dark it doesn't really light up enough even to be able to tell the time. Some luminescence on the hands would have been nice as well.
Second thing I didn't like was the lack of support for Microsoft exchange. Although my gmail account works ok, most of my email is provisioned via my work to my iphone 5. There was no way for me to set this up. I guess it's mainly driven by apple's control of the iOS, denying direct access to the mail app that means the Cookoo app has to be used for everything, however it accesses the calendar directly so why not email? The Cookoo app is also average at best requiring multiple presses often to select the functions.
Another issue I had with the watch was the vibration notification. It is very light and very short. I found I often missed notifications which is poor as for me this is the main reason for having the watch. It's probably on purpose to. Maximise battery life, but it left the watch less useful for me.
My last moan is about the pairing with my iphone. Although I pair the two devices if the watch is out of range of the phone for an extended period I have to re-pair them for the watch to work again.
Overall, although I been a bit negative, it's not a bad watch. I think it's just a bit ahead of its time though and maybe in a few years things will have moved on enough for this to be worthwhile.