GPS Choices

I was wondering if I could get some input from others on a few GPS's?
I have been looking at the Garmin 196 & Street Pilot III as well as
the Lowrance 500 & 1000.

The major advantage that I see with the 196 is that you can use it for
turn by turn directions in a vehicle. I have been looking at getting
a GPS for the vehicle that would do just that. From what I can tell
the price between the 196 and most others are only a couple 100 (for
vehicle).

The main draw back to buying either of the ones I have listed so far
is that it looks like the only way I can get them is to buy online
which also means I don't get to play with it first to see exactly what
features I like or don't like. I have found places that carry Garmin
and Lowrance in the area but none carry any of the aviation models.

Thanks for the help.