I bought this watch about six months ago and have been pretty happy overall with its performance. I also bought the Flowlink along with the watch (and GPS arm band), but I have yet to use it because of the hassle of downloading the Polar software from its website. Even without being to download my workouts, I still take pleasure in using the watch and GPS. It has been invaluable to know what my pace and distance have been, although I'm not sure if the speeds, and therefore distances, are totally accurate. I say this because I have run with my boyfriend who has a Garmin with built in GPS and his watch says that we're going slower than mine does. Regardless, it gives me an idea of where I'm at.
The only issues that I have had with the watch have been one, if you accidentally hit your arm against something while not intending to exercise, you can start the timer. Two, while running in lightly wooded areas (big paths cut between fairly dense trees) the watch will lose satellite connection and will beep at you until it finds them again. I have found that turning the GPS off and then back on again seems to work. Of course, you have to stop and fumble around with it, but that's what it is. Issue three is the fact that the chest belt transmitter sometimes loses the ability to "talk" to the watch while working out. I have found that before each workout, one really needs to wipe down the chest strap (warm water) before starting. Like the instructions say, the strap needs to be moistened before working out anyhow, but a good wipedown is essential to have uninterrupted transmission for the duration of your workout.