What are some of the downsides of owning a Magneplanar .7 or 1.7i ?

I've owned the MMG, 1.7i's, 3.7's, and 3.7i's and would say that Magnepans need a lot of room behind them to really reach their full potential.  I'd say a minimum of 5'--preferable more.

4 pairs I owned did their best square in the middle of the room.
As is common, I put tape on that spot and left them against wall when not playing .

"4 pairs I owned did their best square in the middle of the room. "

Of course if this is where you placed your speakers and found them to have the most satisfying sound that is just fine and of course very audiophile must decide for him/her self what qualities of their Music Reproduction System they find most essential and what characteristics they are willing to compromise in exchange for those preferred qualities. That said, placing just about any speaker but especially one with a dipolar radiation pattern such as Magneplanar "square in the middle" of a room is not consistent with their intended use and certainly not in compliance with their design objectives again especially with Magneplanars.

By putting your speakers "square in the middle" of the room you are getting essentially monophonic sound from your Music Reproduction System. Again this is fine if its' your preference but if your preference is for monophonic sound it would probably be a best course of action to use a single speaker with a single monophonic amplifier and keep everything in the Music Reproduction System monophonic all the way through.

With those speakers relying on a dipolar radiation pattern, placing the speakers square in the middle of the room you have essentially identical sound propagation both front and rear and when these waves meet at the ears of the listener they tend to cancel out. Of course this will not happen exactly that way because of subtle and slight variations in reflections within the room containing the Music Reproduction System but nevertheless the tendency is there an you are going to achieve a very uneven frequency response as a result of this very unusual practice of placing speakers square in the middle of the room.

Again I mean no disrespect to Mr. Shubert and his preferences in sound reproduction but this recommendation for placing speakers square in the middle of a room is most unusual and not likely to satisfy the majority of listeners.

clearthink,

What you are saying about getting mono sound from Maggies in the middle of the room isn't making sense to me.  First, it doesn't seem to make theoretical sense.  Second, in practice, I used to have Quad 63s (diopoles) in essentially the middle of my room and they produced stupendous stereo sound and imaging.  (I tend to like closer to nearfield listening, so most of my speakers end up closer to the middle of the room).

I've never, ever heard a speaker of any type, dipole or otherwise, sound mono by being placed well out into a room.  And placing a speaker into the room tends to minimize room issues.