In reply to higherclimbingwales:
I upgraded from an eTrex H to an eTrex 20 last year. I find the maps useful - I use OpenStreetmap in the UK, which is free. You get GLONASS, which helps speed up the time to get a fix and gives better accuracy as the unit can usually see more satellites.
However, best of all is I get around 24h battery life on the 20. Can't remember exactly what I got on the H, but it was about 1 days walking. I leave the unit on all the time while walking, so I can download a trace of exactly where I have been. With the 20 I can easily get 2 days walking and usually 3 on one set of batteries.