Just saw this thread...

I use (extensively!) the Garmin etrex Vista. It's tech similar to the 60csx, with more screen pixels, but smaller size and smaller (fixed size 24 Mb) memory, and really slow serial port transfers.
If were to do it again, I'd look really close at the 60csx. The ability to add your own mini SD chip is sweet, as that should let you pre-load varios map combinations ahead of time. I couldn't find a "limit" on chip Mb size usability (will it take, and use, a 2Gb chip??), but remember the data sets from Garmin are HUGE, multi CD, >2Gb collections. I use both Topo and street of the same area I plan to explore, it helps for legibility! Note: the topo maps can be loaded into the GPS units 1 map at a time, and the maps take typically 100-300kb of the gps's storage ability, whereas the USA street maps are loaded in 7Mb files, usually a major chunk of a state as one block. So only the Vista has even a reasonable chance at being useful (among the etrex series) if you want both maps or maps of a lerge area. I was able to load all topo maps between Vancouver BC and Denver CO along the hiways I was travelling, including a bunch around Moab, and Silverton as well. But on the old serial interface, it takes ~45 minutes to do that...

I find the GPS is soooo handy now that I can't travel without it!
Even used it to take a lengthy detour through the streets of Tokyo, and measured the real speed of the bullet train (287 kmph)! Here's where the etrex's small size is a bonus. But it comes at the expense of antenna sensitivity (the etrex series headache!)

Any Garmin that can upload/download can also be used to turn your laptop PC into a full-screen GPS mapper, showing current position on any map you have preloaded. And the laptop harddrive will out-store ANY memory chip!
All Garmin maps come with the Mapsource program, which sets up the maps to be usable on the PC you use to upload/download.