The new line of Etex are the 10, 20, 30. 10 is basic, but has high sensitivity, the 20 adds computer inteface/mapping, the 30 adds e-compass and altimeter sensor.
You are spot-on, sir.
The 30 was a good bit more in $$$ so, I decided that I could probably live without a barometric altimeter and e-compass (especially since I don't know personally what it's like to have them) and still have a good unit that does what I need it to.
I'm really looking forward to using it in WA here in a couple of weeks.