I'm been an eTrex user for quite a while (6 years). I've used an old ETrex Vista (with a compass) and and eTrex Summit and eTrex Legend Cx (both without the compass). Personally I don't need the compass, it requires more power (only slightly more though) and it needs frequent recal (both for batteries and major location changes), and in my opinion, doesn't force people to learn the basics. I'm no luddite, but do yourself a favor and buy a good Silva.
(http://www.silvacompass.com/p-43-trekker-420.aspx)
It needs no batteries and will teach you the basics of overland navigation (knowing your declination, reading a map, etc...) BE PREPARED.
My $0.02.
Chris