I have a pink Polar F6 and I must say I prefer it over my Polar F4, which I retired a few months ago. However, for some reason, when I go running with the HR strap that comes with the watch, I don't get a reading. I have to wear the strap backwards and it is really uncomfortable (I suggest you get one of those soft straps, instead of the one with the big plastic middle section).

It is very easy to use, and I like it a lot.