1. The size is good for my wrist. I would not call this the most comfortable device on my wrist, but I am slowly breaking into the band and its starting to get a lot better even in the few hours I have had it on. I am finding that it is most comfortable for me with screen on inside of wrist.
2. I did not really like the way it looks but its quickly starting to grow on me. I really like the band side of it and since I am wearing the screen on the inside, the outsize facing portion of my wrist looks good with the nice black band. Under the hood it is SO good that I am ready to overlook the cosmetic appearance!
3. You would be surprised that how good the interaction works even on this tiny screen. I have had no problems interacting with the device. The notifications and haptic feedback is great and I can quickly dismiss them with a single swipe-click. Whats really interesting is that I am finding myself use Cortana a WHOLE lot more. his morning while driving I just mumbled into my wrist and lo and behold, I had navigation running on my phone!
4. For most part the functionality is great, for example you can send text messages, emails, reminders etc. For things where Cortana has to show you a lot of info (like a web search) it says that she has opened it on my phone, and I should see that! Things like weather, conversions or quick questions, she answers in text form right on the freakin band!!