The Magnepan 1.7 is one of the smoothest and most consistent sounding loudspeakers I've encountered for a long time. Push almost any music through it, and it's bound to sound from good to very good. There won't be those interruptive moments - or there are only very few of them - when the listener must conclude that Fine, this was it, here's the limit, here the good news ends, here the speaker fails, this and this piece of music simply isn't right food for it, and so and so forth.
In this regard, the owner of the 1.7 can congratulate himself: even if he didn't know anything about sound reproduction he can be fairly confident that his speakers sound good. Frequency and phase linearity of the 1.7 will take care about that, I guess. He just have to make sure that the room won't interact in a way that ruins everything. But even in this respect, the dipole principle (less first reflections) keeps the risk is lower than it would be with ported designs, for instance.
The 1.7 is like a grand vintage mono/stereo FM table radio placed on a corner table. Switch it on, and it sounds smooth, secure, relaxed, unobtrusive, comforting with sufficiently correct tone colors, great vocals, and not perfect but nicely integrated bass. To the sound of a vintage FM table radio the 1.7 just adds more brightness, clarity, volume, bigger soundstage, greater immaterialism etc., but the basic idea of the sound remains.