1.7i has considerably more output capability and a taller soundstage, both issues for the smaller maggies
i consider the 1.7i as the minimum true full range maggie, in terms of top to bottom balance (read: sufficient bass output) and a full life size soundstage
of course, as stated earlier by others, it is all about the room size, setup, seating position relative to the panels etc... and also, of course, the issue of bass response of the lrs/+ and .7 can be solved with proper subwoofer support, and correct stands can raise the image height and let the speaker stand truly vertical