Greetings from Down Unda mate!
Well done on the Ren15a's!
Going from B&W's to ML's... there's no comparison! One's a complete box- cabinet design and the other is box-less. No cabinet resonances, no colorations, zero distortion and pretty much at this level, the only limitations are in the recording itself. Doesn't get any better than that!
Also nice one on the Mac gear. I had the MC452 driving Quad ESL's many years ago, with a Conrad johnson tube preamp, that combination was tops! Later on ventured up to the MC462, which replaced the MC452, to drive ML full range stats. They said that the MC462 had 60% more current capacity, so driving stats would be more efficient... but I really didn't find any significant improvement between the two. I honestly think the MC452 is just as good, not necessarily the case with the latest & greatest. Just my opinion, that's all. Unless it were the 2kw monoblocks.
A good mate of mine, who once had the mighty Maggie's 30.7's, drove them with a MC462 but later on sold his 30.7's back to the dealer. I guess he just preferred his triple stacked Klipsch horns. Driven by three McIntosh power amps, loook out!!! There goes the roof! Incredible dynamics. He was using the C53 mac preamp, nice one indeed!
After you've experienced these ML hybrid Stats, you'll probably never go back to a full box design speaker. It's a totally different dimension!
Now just sit back and enjoy those fine tunes!
WOOF! RJ