I've got a 3206 and I love it. It has more features than I need and is upgradeable (is that a word?) with radar, weather overlay, whatever you'd like to add down the road.
As I understand it, the big difference in the two lines (32xx/42xx) is that the 42xx is NMEA 2K and the 32xx is the old tried and true NMEA 0183.
Others will be able to shed more light, I'm sure.