The eTrex series (or anything with a built in antenna, I suspect) have a bit of trouble in heavy tree cover.

Here in the Pacific Northwest this is an issue. In this type terrain, I think the Garmin GPS V with it's external antenna is a much better selection.

FWIW, I have a eTrex Vista and a GPS III+ (basically a GPS V w/worse screen an less memory). I use them both with the Mapsource software - a must if you want topos.

But you are right, the eTrex series have a lot of cool features and works well as long as you can see the sky pretty well.

-john