Emoto

Yes, but you have toe remove the almost useless 100K topo to have all that space available. You can find much better maps to use that space with. Works for me. Think it possible to move it to either a card for enabling when desired, or just off to a folder on a PC somewhere for re-installation later if one wanted to? I can see some utility to the idea of noting terrain contours when considering routes.

You are essentially correct, however, Garmin is not. The RAM listed on the Garmin page you linked to is not honestly represented. The true difference between the 600/650 and the 650t is 3.6 GB - which is the amount of space the pre-installed 100K topo use. The Montana wiki has much more accurate information. Holy cow! 3.64 GB vs 7.35 GB? (numbers from your link to the excellent wiki site). I'm one of those "you can never have too much memory" people, so to me, this is compelling.

One difference nobody has mentioned yet is that the 650T has half a gig more memory than the 600 or 650. Sure, you can add a card to all of them, but still, half a gig is nothing to sneeze at. Full comparison here: https://buy.garmin.com/shop/compare.do?cID=143&compareProduct=75228&compareProduct=75227&compareProduct=75226