Maggies, have a different kind of imaging. As they are dipoles, the soundstage is set farther back like you are in the eleventh row vs row five for conventional monopoles in a concert hall. They are better for acoustical un-amplified instruments, while the True Ribbon tweeter has nearly 180 degree dispersion (that's what Magnepan says) the midrange and mid bass have a more narrow dispersion and a somewhat diffuse sound. Which I feel is more natural, vs say the 4367's more pinpoint sound. Some people say that pinpoint sound is artificial but we like it because we don't have any visual clues in front of us to focus on.
Maggie's main problems is not what they do, it's what they don't do. Higher volume is a problem, dynamics can't match conventional speakers much less horns, bass impact is less (this can be a good thing if you have thin walls like I do in my computer room), low bass requires them to be really big.
Try their new LRS speaker, several month wait time though. However it is a sample of the Maggie sound, for $650.00 dollars. The LRS and the original Quad ESL 57 speaker were the most live sounding speakers I heard at the last AXPONA, Herb Reichart thought so too. In fact I thought they sounded better than my 3.6's in my heavily treated room. Well minus bass and volume, imaging to die for and so clear and pristine sounding. However if you want to rock out, especially at higher volumes with some bass to for classical and amplified music look elsewhere. FYI they love lots of Power, three hundred watts at @8ohms were used at the show, for some small planers.
So overall I would say their is a big difference, unless all you listen to is chamber music at low volumes. I like album soundtracks like Gladiator, Star Wars etc... and classic rock, prog rock, some Stevie Ray Vaughn, Eva Cassidy, Enya, Manheim Steamroller.
Magnepan is working on a dipole woofer module with conventional drivers, I heard it in Chicago this past December. It's a game changer, and scalable too boot. Bass impact, dynamics, volume are all increased by a lot. One problem is what I heard was a prototype, Magnepan is small brand that moves glacial like in speed, so who knows when that comes out. They are considering selling it as a stand alone product to use with other planer's it's that good. However I don't think it could ever compete in ultimate volume with the bass of the 4367's but it would definitely get it closer.