Interesting concept, ideas...
Just picked up this watch as a gift to myself for the holidays. I have 14 days to return it if I don't like it.
I've had it paired up for about an hour so far. Quick thoughts...
1) The vibration on incoming call is subtle, at best. And it's just two quick pulses, and then it's done. Not sure if this will be a significant help, or not. The visual indicator that you missed a call, might be helpful though.
2) No SMS notification is a bit disappointing, although I realize the product is not advertised as doing this. SMS would be much more useful for me than email, however - given that my primary work and personal email accounts usually each get in excess of 100+ messages a day. I don't need my wrist vibrating 200+ times.
3) Time sync works well, and as advertised. This will probably be rather handy if you travel a lot (as I do) and hate re-setting your watch all the time.
4) Find iPhone - Haven't used this yet (since I have this through iCloud anyway) but seems of minimal value, given that the phone and watch would have to be within ~30 feet of each other anyway.
4) Email notification - as mentioned, probably a bit useless for most people on their main email accounts - unless you don't get many emails. The Citizen iPhone app actually uses its own mail client, apparently (instead of hooking into the iPhone's native mail app) for checking email ... which I thought was a bit interesting. But, this led me to the two interesting ideas for this watch...
4) Set up a separate email account on gmail or wherever, for special messages that need to alert your watch. Whether that's through rules forwarding from your main email account, or whatever - an email account dedicated to the watch itself is probably the best way to go.
5) If you have an IFTTT account, you can setup IFTTT to perform all sorts of actions based on triggers on the Internet, and send an email as a result of those. Did it start snowing at your house? You can have it send an email. Stock reach your desired buy/sell price? You can have it send an email. Your favorite MacRumors blogger post a new story which is in their RSS feed? You can have it send an email. Item go up on CraigsList that you've been looking for? You can have it send an email.
This is a really interesting possibility -- given everything that IFTTT can do. Additionally, I have Belkin WeMo switches and motion sensors that I've hooked into IFTTT - so I can have IFTTT pick up on motion from them, then send an email to my Citizen-specific email address, which will trigger the mail alert on my watch. This could be useful for making sure that the petsitter comes by once a day, while I'm traveling (yes, I could make IFTTT just log it somewhere else, send a SMS to my phone, whatever else ... but that's hardly the point).
We'll see how it goes, whether I keep it past two weeks or not ... but feel free to ask any questions.