I bought this watch as an upgrade to my Garmin FR60 (which is still working fine, but I wanted something that would log my routes via GPS).
I'd researched the models out there and finally decided to go with DCRainmaker's recommendation, following his excellent online, indepth review.
My plan was to get to know all the features over a 3 week period, prior to my half marathon - but in the event, injury laid me up, so the first time I used the watch was on race day!
I haven't used the watch intensively enough to give much of an indepth review, so I'll leave a few bullet-points on my experiences with the watch.
* I love the customisable pages (but wish you could turn off the time/date page in auto-scroll - hopefully that'll come in a future firmware update).
* Virtual partner was invaluable. I ended up using this exclusively during the race - I'd pre-programmed it with the pace I wanted to keep - and it constantly kept me on track. Much more useful than just glancing at your current or average pace, as it gives an overall report of whether you're behind or ahead - and continually adjusts if you speed up/slow down. It takes all the guesswork out of racing (or training) and allows you to just get on with it.
* The vibrating alerts are brilliant. During my race I was wearing headphones, but had no problem missing any of the alerts (eg behind pace in Virtual Partner).
* Set-up and options are very straightforward and easy to navigate. Initially the touchscreen does take a little getting used to when you're negotiating the different settings, but you soon get the hang of it. I'd initially been a bit dubious about the touchscreen, as I'm usually a buttons woman, but it was surprisingly user-friendly - even in pouring rain.
* Speaking of pouring rain, no complaints whatsoever. Worked a charm, with no ill-effects - and at one point during the race, the rain was monsoon-like.
* I haven't used the intervals feature, but my running partner has (she has the same watch). She loves it. Allowing you to set your interval sets and recoveries in between, with a vibrating alert is apparently "the dog's tenticles".
* The HRM strap is very comfortable, absolutely no chafing (which had been a problem with previous Garmins) - and a much better fit than previous models.
I download the workout activities via a MacBook Pro and the ANT+ stick to Garmin Connect. Training Center doesn't run too well on Mac, and Garmin Connect is a ropey online programme overall, but I've been using it for over a year now and it's perfectly adequate for analysing your runs, etc. I also use TrailRunner and RubiTrack. No problems uploading with the supplied ANT+ stick to any of these programs.
I'm looking forward to using more of the features of the watch. I've got a feeling I'm going to love it - and although it *is* comparatively expensive, it all boils down to what you're willing to pay for a training tool. If the features this watch offers aren't important to you - it won't be worth the money. Conversely, if statistics and the features it offers will enhance your training sessions, then it'll be as vital a piece of equipment as your running shoes.
I also have a bike set up on a turbo trainer, with a GSC10 speed/cadence sensor. I haven't used this HRM with the turbo yet, but would expect it to perform as well as the FR60 I've previously been using.