I recently purchased a refurbished 305 with HR, speed/cadence sensor for $175, and I have been very happy with it. The equivalent price for the 500 would be $350. To your point, I have found it very easy to download and to follow courses loaded on the 305. Although the street names are not given, the routes are easy to follow. I should say courses, since there is also a route function which I have not used. I agree that the documentation is sparse, and i have had some glitches with uploading to Garmin connect.

My buddies and I took a wrong turn on a recent metric century ride, and I was able to use the Garmin to find our way back to the course without any difficulty.