the #12 had a (radical) new switch-mode power supply that worked great on paper but, at least in my case, didn't like voltage fluctuations or brown outs.
the power supplies were rebuilt by JRDG as a result and are now 100% reliable.
the amplifiers are beautiful both to look at and to listen to. i can't compare them to more recent offerings, but IMHO you're looking at the same form-factor as the new 725's with two boxes per channel. plus because each chassis only weighed about 32 pounds, one person could set up the amps themselves.
but admittedly Rowland took a hit with all of the peculiar things happening with those original power supplies. and the dealers were taking in $14,500 a set on them. well, that's the good, bad, and the ugly from my perspective.