.....If you decide to give the Polar a try, I'd be interested in hearing about your experience!
So I spend a little time looking through Polar A360 site and also found couple of 1st impression reviews online over the weekend. The downfall for A360, for me, is that it only tracks HR during workouts and the rest of the time is estimation based on HR tracked during the workout. The daily calorie count is from that and data input by the use (e.g., height, weight and so on). Sleep monitoring is strictly motion sensor only and no HR.
On the plus side, week long battery life, water resistance such that one can shower/swim with it. That said, it has microUSB port to charge so not sure how well that's kept dry, if submerged.
Did not plan to get a B2 due to lack of better iOS integration with Apple Health app but didn't want the current Apple Watch as I find it too chunky for my taste. Was hoping to make B1 last until 2nd gen AW but to no avail. B1 peeled inside and started having problems tracking steps as well as the area near the clasp started to separate apart (super glue works...) It was looking bit too sad to be wearing publicly, so needed something.
Got B2 today at the MS store. They offer to replace my B1 for free but once I tried the B2 on, it was so much more comfortable that I updated to B2. Sadly, they only gave me a $25 credit towards B2 for my B1 - pays for sales tax and couple of dollars left. Its just a price for supply and demand I guess...