Advantages Cheap, solid, compact, has all the basic features required
Disadvantages No mapping software, have to manually enter locations
I bought an eTrex about 14 months ago primarily to help me GeoCaching (which is a hobby finding hidden items often in remote or countryside locations around the country). My main use for the eTrex was to use the built in GPS. This model is the cheapest in the range but has a lot of functions that can be useful. I found the GPS pretty good, it normally picks up the signal within 20-30 seconds in clear weather, and it can get a little slower in cloudy condition or under tree cover. The accuracy of the reading in my experience is also very good; I can normally pinpoint locations to within 1-2ft ...