COunterpoint SA-220 is one of the best amps I have heard on Maggies. There are two of the newer versions for sale on Agon now.
Having been a Maggie owner since 1979 and gone up the ladder with various models,I have found that any quality amp that doubles its power into 4 ohms has always worked well.Doubles is power,not merely increasing its power is what counts.All the above amps mentioned should make those babies sing.Would like to add that the older levinsons No.27/No.23/are superb amps for Magneplanars.Mate with a fine tube preamp and you should be in nirvana all day long.
I have had great luck with three amplifiers - an Audio Van Alstine 250 wpc FETvalve hybrid ampflifier (heavily modded, including bybees), Canary CA-160 tube monoblock amplifiers, and Tube Audio Design Hibachi monoblock amplifiers.
I was persuaded to try the tubed Canary monoblocks because I was under the belief that tubes don't sound good on maggies. That was clearly wrong as they sound wonderful driven by reasonably high power tube amplification - at least these tube amps (modded by Bob and Gary Backert at RHB Soundezign).
I had an Accurus amplifier that was modded with bybees and some power supply changes that sounded OK but not as good as those listed above.
I had the Rotel RB-1070 with my 1.6s for only a few months. It simply didn't have the guts. I liked the Rotel 'house sound' and had I bought the model up, the RB-1080 I may still own one.
The 1070 has no factory 4 ohm power rating, though the bridged mono rating into 8 ohms implies a 4ohm power of about 180 a side.
While many panel owners like the 'd' amps, you can't go wrong with any of the mentioned amps.
Time for an audition? How long is 'a while'? I'd be reluctant to let any electronics sit for more than say......a year, before using.