My husband and I have the 305. He upgraded to, I guess the 705 (whatever the next one up is), but decided it was so much money for what you get. He went back to using the 305 and has been intending to Ebay the other one.

We have had problems off and on with our Garmins. Dh is good at figuring it out usually, but we have had to have one or both replaced with refurbished ones. They can be annoying, but yet they're so great too.

My friend just got a 305 and was having a hard time getting the "speed" working properly. My husband turned it to GPS mode for her, instead of having it work with the cadence sensor or whatever sensor figures out speed, and it works fine now. He says he usually can't get his to work without putting it in GPS mode (where it figures out speed from satellite or whatever). He moves his from our tandem, to his MTB, to his road bike .. so he's had to mess with it on several bikes ... plus mine on my road bike and the tandem. He's my "fix it" guy!