The new "H" models of eTrex have a lot going- memory card, road route calculation, but most important is higher sensitivity. My old Vista would lose signal all the time under trees, while my new Vista HCx holds on to a signal tight even in my pocket while under trees. I bring it jogging all the time, and even in a fanny pack it never has a skip in the track log.

EDIT: By the way, they do have labels on the buttons- there's a cryptic icon molded into the rubber button. Good luck figuring out what they mean though!

I thought the x mean it had the memory card not the H.

The "x" does mean that the unit is capable of using the microSD cards for memory. The "H" indicates the newest etrex models with the more sensitive chipset. If you go out today, you will find models with no letters after their name, models with just "Cx," indicating the expandable memory, and models with "Hcx," that have both expandable memory and fantastic reception.

The kicker is that all three go for the same price retail. If you go buy one, make sure it is the "Hcx" model.