Posted for "John Barrett" <2thman@olympus.net>:
Best advice I've heard so far is: get the CD rom simulator and try it out on
your computer.

[ or grab the program directly from
  http://www.garmin.com/software/TRAIN530.EXE
  http://www.garmin.com/software/TRAIN430.EXE   -Rob ]

I have a GNS 430 - and have used the simulator extensively. For my mind the
features aren't quite as intuitive as I'd like, but they are fairly easily
learnable.

I bought it because I wanted my second com, as well as my VOR/GS to be in
one box and I liked the IFR TSO with color moving map.

Its appeal for me mostly revolves around the fact it combines several
features into one  box.  This is because it will be backup to the Sierra
Flight Systems EFIS system and I want to save  weight/panel space/clutter
etc.

Regards,
John Barrett
L IVP - building