Polar F6...any reviews?

That's what I have!! I really like mine. I got it for a really great price too, on clearance for 69.99CDN. I have had no problems with it so far, easy to use!
I have not sat down to try and figure out how to upload the monitors info onto their website, but that's fine, cause i enter it all here anyways.

I don't think you can go wrong with any Polar. They seem to have the best reputation.

I've never used the F6, but my wife had the F4, and she didn't really care for it. I had an F11, which she inherited a few months ago when I upgraded to the FT60, and she likes it much better.

I think the main difference for her is that the F4 (and likely the F6) doesn't really keep much historical workout data. I think once you start the next session, you've lost the last one. The F11 does better.

For just knowing what your heart rate is, they all work about the same. Depending on the gym equipment you have access to, they are about the same. It will give totally different results. An elliptical machine calorie display will always exceed what the polar says (for me, by 20-30%), bikes will tend to underpredict.

Personally, for weight loss, spending the money on the FT60 is the way to go. It will set up a training plan for you (weight management being one of the three options), and track your progress to the plan. It was a bit daunting at first being "told" by my watch I needed to spend 5 hours a week at the gym (now, its up to 6) but its great motivation, and work to get my "trophy" every week (warning-don't overtrain at the higher heart rate levels) . I've been losing 2.5lbs a week since I got it 8 weeks ago, and my fitness test scores are way up. Relative to the F6, it probably costs only about one or two personal trainer sessions more. It forces more focus on the training bands (weight loss, cardio, extreme) which the F4 doesn't. If you have the discipline to track and maintain it on your own, that's great, but the better watches will make it clear, and the three training zones really do work!