I have one and I think it is a great unit. You can download free topo maps off the internet for it too. It gets the satellites real quick and the batteries seem to last long. Can’t go wrong with it if you aren’t concerned about a lot of bells and whistles.
I have the GPSMAPS 62S from Garmin and I have been completely satisfied with it… I think the Etrex 20 does support Birdseye so I recommend the Birdseye Subscription and download all the aerial photos onto Basecamp… Great programs with Garmin
I have the Etrex 30 (next step up from the Etrex 20). I love it, however the last time I tried to update the firmware on it, it bricked it. Of course I am about a month or 2 out of the year warranty so its going to take a service charge and shipping it to Garmin to get it fixed.