Mye stands - are a must have for Maggies to perform at their maximum capability. The improvement has to be experienced. 1.6QR with Mye stands easily outperform 1.7 without Mye stands in my experience.
Several friends and I all sold magnepan speakers in the 80's for the same dealer. They were stunned, amazed, etc., at the sound of 1.6QR with the Mye stands vs without. Midrange and HF sound quality has hugely improved, any trace of hardness in the upper mids was removed. The speakers absolutely disappeared,the soundstage could be wall to wall with added depth (dependent on the recording of course), and the highs sounded like that produced by a real quality true ribbon tweter.
If you want more body, go with the 1.6QR. I found that the 1.7 is more coherent, has more delicate highs, and is maybe a little faster on the low end, but also much more critical of associated gear and setup that the 1.6QR. That might mean they are more linear/accurate in response, but I never 'warmed' up to them.
Using a hifi tuning fuse also made a noticeable improvement on the 1.6QR as did bipassing the jumpers.
Try all of this before actively biamping. Also, I found that passively biamping the 1.6QR made little difference.
I drove the 1.6QR with relatively modest gear: modded Marsh 2000t pre, Krell KAV25a0a, modwright sony 9000, and cheap cables(MAC, Speltz, PS Audio). The Krell was an excellent match with the 1.6QR. And the 1.6QR easily handled that power and easily filled a large listening area 20x 28 and could play loud! Oh, I miss that room.
Your mileage may vary.