I've had my SmartWatch for just over 2 weeks now, and while I am still happy with my purchase, there are a few things to bear in mind if you are considering buying this watch.
1. It requires a constant bluetooth connection to an Android phone to do anything - it won't even display the time if you have not connected it at least once after powering it on.
2. The device itself is essentially an extra, remote screen for your Android device - although it may appear that way, the various SmartWatch apps available on Google Play do NOT run on the device itself, instead they run on the phone and their output is sent to the watch. This means that any apps you have downloaded for the watch will be constantly running in the background on your phone. So, if you have an older Android device with not a lot of memory, this could be a big problem and cause your phone to slow up considerably. I have an Xperia Arc which has 512 MB RAM, and I would say that is about the minimum spec of phone you should try using with this watch. I need to turn off my bluetooth connection (which automatically shuts down the SmartWatch apps) when using memory intensive apps/games on my phone or performance will be affected.
3. The bluetooth connection requires 2 apps to be installed on your phone, LiveWare Manager and the SmartWatch app. The bluetooth connection is however still not perfect, and drops out from time to time. This is improving with new LiveWare releases, and I understand it's MUCH more reliable than the old LiveView connection, but it's still not perfect.
4. The music player widget will not show the album art and track name (as shown in the pictures here) unless you have a Sony phone and are using the stock Sony music app. The controls still work for other players (like PowerAmp).
5. The email widget also only works if you have a Sony phone and are using the stock Sony email app on your phone (which I fortunately am), otherwise the best you can do is get one of the SmartWatch notification apps from Google Play to send email (and other) notifications to your watch. Unfortunately, these notification apps do not allow you to read the text of emails on your watch (unlike the email widget) and also require an accessibility service running in the background constantly on your phone, which can take up quite a bit of memory.
6. The screen is not good in bright, direct sunlight. Unfortunately, there isn't a way (yet) to adjust the screen backlight brightness.
Otherwise, the SmartWatch has worked very well for me. It's just about right size-wise, battery life is ok (given its OLED screen) and it responds well to touch gestures like swiping and pinching.
The Motorola Motoactv may well be a MUCH more powerful Android SmartWatch (which you can also root and run Angry Birds on!) but it is also over twice the price of the Sony watch, which probably offers pretty much all the functionality you'll be looking for in a SmartWatch anyway. As long as you can live with the points mentioned above.