I have a Garmin 500, and have been pretty happy with it. The customizable screens are great...you can have 3 pages of data with up to 8 fields of data on each page. You might find it hard to read while riding...but it's possible.

With regard to the "Course" feature. You can indeed prepare your route on the various websites (MapMyRide, RideWithGPS, GPSIES, etc.) and then download it to the 500 as a .CRS (course) file. The 500 does limited navigation. It's at this point that I have to stop talking about it...because there appears to be a Garmin software problem that is more likely to occur when riding a COURSE. There have been reports of the unit locking up and losing the data for that ride. This has kept me from playing around with the COURSE feature anymore than I have.

Garmin is aware of the problem and says that it is working on a firmware update, but has not provided any type of timeline. With a personal history in software development, I can certainly appreciate their hesitancy in giving themselves a deadline.

For more info, I'd like out the Garmin Edge 500 forums at https://forums.garmin.com/forumdisplay.php?f=219 ...just keep in mind that as with most internet 'product' forums, you're going to find more people with problems...

Good luck!

Charles