BP-fan: I did the fitness test and got 57 which apparently is elite (i don't care if its not accurate, it's a good ego boost

) but when i was just sitting down trying to work out how to use it, my heart rate was apparently around 90, which is really high isn't it? so I don't get why thats happening.
Simple; You are so excited learning your new HRM your pulse goes up which - accidently - confirm how good it is. 
No, seriously; a restrate of 90 sounds fishy; either the emitter isn't properly fitted or it is flawed (or perhapes my joke wasn't so improbable as one might have guessed?). I'd try to check the emitter. Good choice, though both Suuntu and Reebok have good HRM's as well. As long as you feel satisfied that is good enough.
I've had Polar M22 earlier, but it only worked for +4years (!) so when it was time to replace it I too got myself an F11 and haven't regreted it a day (that purchase was 1½ year ago). My wife has an F6 and it's that not much that differs; the program (if you choose to use it) mainly, so don't wonder whether you bought the right one or not.
Just don't live by the HRM; it isn't a hindsight, I use the HRM each time I train (attending or teaching, regardless) but I only use it to confirm/deny my shape for the given day ("How did I feel, I felt tired today. Oh, my, +700 - maybe my shape wasn't as bad as I thought" / "Damned that was good, *what?* only 400 @ bp? ah, must be yesterdays dehydration!" etc).
It can help you be more selfaware, read your own signs better but it can *never* the "the truth". It's a tool - no more, no less.
PS. ....and it works as a motivator in case you wonder whether you deserved that
/
/whatever was righteous or not.
DS.
When everything is said and done; you can say it's easier said than done! :-D