I had a pair of RM30's w/ Auricaps, silver wire, and better, not best cabinets--cherry. I had the long slot waveguides and didn't like them as well as the bare drivers. There was greater clarity with the bare ones, and more transparent in my system. When I bought RM40's, I bought a set of the newer waveguides from Brian, but never used them on the 40's. Most of those I talked to or read their posts (call it 80%)liked the sound of the newer ones better than the slot style. It was a crapshoot on the newer style vs. bare drivers--very even in preference. Looks wise the slot style would be preferred by wives and girlfriends over either the newer ones or bare drivers. The new ones are supposed to widen the sweetspot. The drawback on this point is they will send more lateral sounds off the sidewalls. The clarity would still be a tad greater on the bare drivers, though. Hope that helps. I was a VMPS demonstrator in the Chicago area fro the last 4-5 years Brian Cheney was still going.
Bob