Bought this last week as an upgrade to the 920XT. Actually my 920 died and was replaced by Garmin so I just sold the new replacement, if it hadn't of died I probably would have kept it. First impressions, really nice watch, feels a bit more prestigious than the Forerunner, but not cheap at $700. The metal bezel and buttons give it a good solid feel and the extra weight isn't noticeable. Actually when in the shop I tinkered with the 735 which felt very lightweight and plasticky in comparison and the 935 is even lighter. Looks good as an everyday watch, something you could wear out. I loved my 920, but not a good looking watch Navigating the F5 seems pretty intuitive, I'm still finding out about the various new features and haven't had a good play with it yet. The screen is nice and large and clear, it was easy to quickly glance at it when swimming open water to check time and pace. I'm used to the square face of the 910 and 920, but the circular face of the F5 works well, even with 4 fields. There are a few cool features such as music control, but I can't see enough to warrant an upgrade from a 920/F3. The battery life is excellent. I bought it Thursday and have yet to charge it, 42% and that's after 1 x 2km OWS, 1 x 3km pool swim, 100km ride, 7km run, 12km treadmill run and a shitload of mucking about with it. One thing I noticed on my 7km run was my instant pace was jumping about a bit, mostly sitting consistently on 4.15, but then I would look down and it's at 6.30, then 5.30, then it would settle down to 4.15 again. My 920 never had this issue. Heart rate monitor seems relatively accurate, I haven't had a chance to look at the Garmin data yet, but every time I checked it on ride and run, it was reporting back roughly what I expected it to. Doesn't work in the water, but I don't think it's supposed to is it?