The 511 is a fine knife. I've picked them up from the tables at Knob Creek, but they're close enough to a Dumpster Mutt (and I have lots of those) that I haven't felt the need to buy any 511s. However, in my opinion, the RMD is in another league -- it fits my hand nearly perfectly and balances great; it's a little heavier and more expensive than a DM or 511, but is worth it to me. The original RMD is one of the top designs to come out of the Swamp and a best of breed knife.