Which GPS?

Am looking to purchase a GPS. As this is the ROTORCRAFT forum I don't
need to say (but I will) that the gps must be easy to see, easy to
operate (1 handed?) and light weight (in case strapped to kneeboard).
I have been looking at the Garmin GPSmap 196. It has a black and white
screen not the color. It is HIWAS (according to the published info)and
12 satellite receiving capability. As I don't have access to a live 12
volt power supply (cannon or cigarette) battery drain is also a
consideration. Given all of the above is this a good gps or is there
another that you all would recommend. I appreciate any and all
responses as I don't want to spend much $$$$$'s and wind up with the
wrong one. Thanks and I await your responses.......