Hi Ron,
I try in most set-ups to make an equal lateral triangle between the speaker distance apart and the listening distance. I really like a wide soundstage so I am guilty of placing the speakers further apart than I should to maintain a sharp center image - (by the way the 3 channel stereo demos by Magnepan really help maintain the center a lot better so that may be where I go eventually)
Yes the MG-1.7 is designed so that the best impulse response is when you`re sitting on axis with the tweeter whereas the MG-1.6 has the tweeter pointing over the respective left and right shoulder. With the tweeters on the outside you get a wider listening area but less focus. I have them set-up with the tweeters on the outside and toed in significantly.
james