I was faced with pretty much the same selection criteria as you, and was tempted by the Garmin GPS12 having tried a friend's unit. No frills, but all I wanted was a good "second opinion" on my map, compass and eyework!
I actually ended up with a GPS76, actually wanted a GPS72 but not available in the UK then and couldn't wait! To me, these appear to be pretty similar in functionality to the GPS12 but with a better screen, both dimension and quality wise.
Haven't regretted it (but must admit being jealous of my GPS12 friend who has since upgraded to GPS196!!!)
RC