A HR Monitor Watch is one of those things that when you get your first one you wonder how you ever could live without one... They are addicting and take your excerice to new levels, whether you use them for hardcore workouts or just want to use them for walks. I can't imagine working out anymore not having my HR on me.
I had a Polar F6 before this one, and to be honest I did like that one very much. It was a basic, good qualitve HR monitor from, according to me, the best manufacturer in the business (Polar) that gave me all the information I needed (heart rate, calories burned). The biggest drawback with F6 is that you can't change battery yourself, and considering that the battery life seems to be around 10 months with about 2 hours use/day (Polar says 1-2 years with a 1-2 hours use each day) it gets pretty annoying not being able to change the battery yourself.
So... I wanted to upgrade a bit, but not too much. My need is still a pretty simple HR monintor with some basic features like the ones F6 has. But most importantly, I wanted a HR that has a user friendly battery change so you can do it yourself (which FT60 has). FT60 is a basic HR monitor, but it DOES have some more cool features than the most basic ones (like F6), so it's certianly an upgrade for me being used to the F6. After using this for about two months now I only have the best to say.
If you're thinking about F6 or FT60, I'd say put down the extra money and go for the FT60. Being able to change battery yourself is sooo much worth it.