Depends if you really need it or not. I have one and it is one of the best thing that has happened to me. Waterproof is awesome, I only take it off to charge it. The shower, pool, etc. it's really convenient.
Anyways, I am not allowed to use my cell phone in the hospital I am at, so it's nice to be able to see text, emails, and phone calls without bringing out my phone.
I also can change the time format from 24hr (which the hospital uses) to 12hr for when I go out or anything.
The own the rubber first gen. I am thinking of purchasing the new steel so when I dress up and go out it won't look so cheap, it looks pretty nice.
I'm hoping the new App Store will bring some more cool features but I'm not sure what else id need. You can buy one at best buy and if it doesn't work out, always return it.