The newer eTrex Legends and Vista HCX - (note the HCX) has quad-helix antennas. They use the Mediatek chipset. The 60CSX and 60CX also have quad-helix antennas but use the SIRFIII chipsets.
It's my understanding that the quad-helix antennas and the newer improved chipsets are what set these units apart from older Garmin units in sensitivity and reception. This is a priority for me
Both the Etrek Legend and Vista HCX and 60CX and 60CSX use Micro-SD cards and downloadable maps. Another key feature for me
See geek talk but very thorough here
http://forums.groundspeak.com/GC/ind...c=168173&st=50
I'm going to take a look at them to see how the user interfaces compare