I am currently using the Garmin Etrex Summit HC. It’s the second GPS that I’ve owned (we do a lot of geocaching too, so within my family we have over 6 GPS’s) I am a big fan of the eTrex and often just start it and stick it in my jersey pocket until I need it.
Overall, the eTrex series is really nice for what I need. It is a little big to mount to the handle bars (and I’ve heard that if you want to mount it make sure you put something in the battery pack area to snug it up). Like I said though, I have mine in the pocket and it works fine. Overall, I use Garmin’s MapSource software and the TopoGraphic add-on to map maps (plus I love that it shows elevation changes)
If you have any question/problems, let me know – I know the GPS pretty well.