I have three old National guitars (and a mandolin), a 1936 brass bodied Style O, a 1931 steel bodied Triolian, and an early 1929 wood bodied Triolian.
The wood bodied Triolian is by far the loudest (it may very well be the loudest National I have ever played) and has a phenomenal amount of bass. It is so terrifyingly loud that it can actually be a little difficult to sing over.
The brass Style O works best for standard tuning playing, I keep the two Triolians in open tunings.
