I have nothing but respect for Magnepan who makes great speakers for very fair prices. I have been a MG-20 owner for close to 20 years and still find my bi-amped and Myestand pair to compete with virtually any speaker on the market.
However the hype about the new .7 series speakers, not by Magnepan, but by the high end reviewers is starting to get a little absurd. The 1.7's and the 3.7's are not transformational steps above the 1.6's or 3.6's but evolutions on this generation of speakers.
I have heard both generations of speakers and the new .7 series does not "kill" the .6 speakers, they are different, but not necessarly significantly better. For a matter of fact the 1.6's and 3.6's allowed the user the option to bi-amp either speaker. The new 1.7 and 3.7 does not allow this option anymore, it is not clear if the new 20.7 will or will not have this option. I have never heard either 1.6's, 3.6's, 20's, or 20.1's ever sound their best when they were not bi-amped and had to use the rather poor passive X-over that comes with the speaker.
At least three individuals that I know wanted to upgrade from their bi-amped 3.6's to 3.7's and found the performance of the 3.6's bi-amped compared to the 3.7's with their passive x-overs, chose not to make the move because they thought the performance of the 3.6's bi-amped was still better then the 3.7's.
They are all great speakers and bargains for what they cost, however if I was in the market right now and could get either a pair of 3.6's or 20.1's for what they are being sold for and then Myestand and bi-amp them I would have one of the best performing speakers for a very reasonable price.
So I want to be clear the 1.7's, 3.7's, and new 20.7's are terrific speakers and well worth the money, but not "heads and shoulders" over the last generation of Magnepans as the always looking to create a buzz highend reviewers would have you think.