i'm getting good results from a tecnica 4x5 with a camed 150 and an 80 which is not cammed but i put a couple of infinity stops in for it and focus on the gg, with the 80 i've been using speeds down to 8th of a second no sweat...

the 4x5 is enough though, i can't see any advantages to using an 8x10 hand held, on a tripod yes but hand held... with the 4x5 you have the entire history of press photography as a reference, wegees prints are fantastic for example and there are a couple of threads here worth looking for on hand held 4x5.