Magnepan mg1.6 vs mg1.7 bass quality?

Lecram, I never had the opportunity to hear the 2.7's, so I don't have that as a point of reference. I agree the 3.7's may be a stretch in your room, but mine are in a room 15 x 19 x 8. Take a look at my system pictures to get a feel for how they look. The funny thing about the 3.7's is that they integrate with the room MUCH better than the 1.6's did. I was able to take most of the room treatments out of the room.
I'm not a huge fan of Bryston and Krell amps with Maggies. I do like the SS Cary amps (obviously), so you might think about that as another way to warm things up a bit. I still think the best move is to pick up a nice REL sub and see if that gets you where you want to be. You can snag a used R-218 or R328 pretty cheaply. Even cheaper if you go with an older REL.

Pass also seems to be a great match, "Then I tried a set of Pass Labs XA100.5 mono amps with the 1.7 which immediately had me revising my opinions of the speakers";
http://www.tonepublications.com/MAGPDF/TA_030.pdf

Once I added mono block power the speakers bloomed. They are thrilling now and much fuller sounding than the 1.6's . The new crossovers are made to do that. But if you have the 1.6's I would only change to the 3.7's....

Thanks guys for the advise. I plan to buy the 1.7 then do a side by side comparison after break-in of the 1.7. If the 1.7 really proves superior, then i can sell off my 1.6 which is coming off 10 years already.

Cant really go for the 3.7 as it would ruin room aesthetics, and i would never really be satisfied with the bryston 4bsst2 running a 3.7, and moving up to the 14bsst2 or other higher powered amps would cost me so much money which i am not willing to spend

I was really just hoping that the 1.7 can improve on the 1.6's detail on top and bass punch down low.