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

All speaker design are compromises. Every listener has to realize his priorities in the sound of reproduced music, and then find products that have been compromised to achieve those same priorities at a given price point.

Panel speakers like Maggies provide a sound NO box speaker can, regardless of price. If "that" sound is what one has as a priority, it’s failings can be accepted and lived with, while the failings of a box speaker, though superior in some ways, can not.

I recently took a magnet, and tested all the parts on the terminal plates of a pair of Tympanis. The parts appear to be the same as on current models, and here’s what I found: The speaker terminals (those short little tubes into which you insert banana jacks or bare wire) are ferrous! Steel, I presume. So are the nuts which secure the terminals to the plate, as are the rivets which secure the fuse blocks to the plates. All the other parts---the plate itself, the tags onto which the internal wires are soldered, which are then installed onto the backs of the terminals, and the fuse holders, are non-ferrous, aluminum perhaps.

The steel speaker wire terminals have to go. Steel?! Luckily, the Cardas binding posts fit perfectly in the holes into which the stock posts were installed, no modifying needed. However, the Cardas posts are just slightly deeper than the cavity in the MDF speaker frame, so one needs to move the plate out from the frame a little. I got some aluminum stand-offs at my hardware store, putting them between the plate and the speaker frame, and it works perfectly.

The fuse blocks are connected to the + speaker terminal with round clips, so when the terminals are removed, the fuse blocks can be left disconnected if one chooses. Another piece of trash removed from the signal path, for increased transparency.