Purchased the product about two months ago and have used it exclusively for running and biking. Technically I have not had any issues and all the accessories, (e.g., bike speed/cadence, HR monitor, and quick connects) have connected and worked beautifully. I ran a 5k race in my first use and the GPS accuracy was right on the money. I have run several times after that and no disappointments - light years away from my old Polar!
Regarding the bike use, I took some time to get all the settings (e.g., display) the way I like them, but now it shows me everything I need during my rides (perhaps more than I'd ever need). The unit is big enough to display all the metrics and it's not bulky at all.
No swimming yet, but I think the unit works great overall. It does everything I need plus more!