I have the Edge 305 - since last summer. First ride I used it, it was pouring rain. The speed/cadence sensor hasn't worked since! I have since read that they don't do well with wet weather which pretty much makes then useless in the PNW. I still use it for the gps, but I haven't bothered trying to get the speed/cadence sensor to work again. I do like the large display but I don't see how it could be used for running or any other sport as it is relatively huge and it has no wrist strap.

I used a Polar (the older model 725i) and loved it until it needed a new battery. It worked great for 3 years - cadence, speed and HR were almost always spot on. The only issue I encountered was interference with my headlight, but once I shielded it, that was solved. I sent the wrist unit and strap to Polar to get new batteries and it hasn't worked since.

Now I'm kind of in the market again. For now, I bought an inexpensive Timex HRM to use for running and gym stuff and I still use the Edge 305 on the bike. I'd eventually like something that will work while swimming, so I'll probably end up with another Polar. I'm just not to the point where I need it yet, so I am holding off. When I'm ready, I'll use Polar's 'trade up' program and get a nice discount (assuming they still do it).