The 511 and Dumpster Mutt handles are the same size; the only difference is the texture - my DM has the old smaller Basic series handle. The 511 handle has a slightly textured feel all over, which is excellent! The difference of opinion about the handle sizes was the same with the Basic 3 or 5 vs. the Basic 7 or 9 - some people did not like the smaller size handle, but I disagree. I think it probably depends on the size of an individual's hands - mine are average size, and I like both the smaller and larger Res-C grips. For me, the 511 is one of the best knives produced by any of the Busse companies in a long time; for the blade size, the handle feels great in my hands. I recently used a 511 to cut up a large, extra-thick cardboard box, and I was surprised how easily the 511 sliced thru the unusually thick cardboard. I really like the Basic knife series, but I especially like the 3/16" blade thickness of the 511 - it is definitely a keeper!
Gene