I was all set to order the 60C this morning when I did a last minute check to the Garmin site and saw the 76C and 76CS.
I definitely want the larger memory and also the Marine Point database that is preinstalled on the 76 series. I have the map 76 and the tide and marine marker info is very convenient to me. Most important though is the buttons on top. I find this position allows me to have a more secure single handed use of the unit with no chance if dropping it. With the buttons on the bottom, the unit is top heavy and hanging off/out of the hand and the thumb is contorted to press the closer buttons. Just my personal findings from my past usage. Maybe it was a blessing in disguise that I had trouble finding stock on the 60C because I am definitely waiting for the 76C!