I'm looking into buying a hand-held GPS, for hiking and MTB'ing. Basically I'm sick of making wrong turns and having vague ideas where I am, and it's a new toy

The unit that seems to suit the level that I want is the Garmin eTrex Legend which I can source here in CH for about CHF260-

Firstly, does anyone have anything good or bad to say about this unit, or have alternate suggestions?

Secondly, more Swiss specific, is not having an altimeter in the mountains a real issue? (ie the positioning can give false readings due to varying altitude) Also, does forest cover impact greatly on the ability to get a satellite signal for this model?