1,2,3 fingering also allows the 320033 version of the G chord (I think this is the one Midchuck is calling the "Tony Rice G"). This is very prominent in "Take it easy" by The Eagles, to pick an obvious example. I don't like it as much as the regular 320003 version, but it has its places - as do the 32000x and 32003x versions.

It also makes possible an alternative G7 with 323003 which allows interesting mid-range runs instead of the bog-standard bass and treble runs.

Graham.