If the basemap installed in the new Etrex is the same as that in the old, it's little better than useless. Pretty much trunk roads only. Subject to the thread here about difficulties loading OSM into the 30, I would have thought OSM was your best option.
I have the better Garmin mapping on a micro-SD, and that is fine (I actually prefer it to OSM as it has less clutter for on-road riding) but it isn't cheap. And will eventually be out of date in some critical areas.