As a long-time Maggie (and other dipole planar loudspeaker) owner, let me say that the two main considerations in their use are:
1- Room size. If your room does not allow them to be placed at least 5’ from the wall behind them, they are probably not right for you. 3’ is often quoted, but that is actually insufficient in creating the desired minimum of a 10ms difference in arrival times between the front and rear waves of dipole speakers.
2- Amp power. For Maggies, the more the better. A great amp for the 3.7i is the Sanders Magtech. Due to their series crossovers, the .7 series Maggies do NOT allow bi-amping (bi-amping with a ss amp on the bass drivers and a tube amp on the tweeters has long been favored for Maggies), so you need a real good high current power amp.
With enough space and power, magnetic-planars have their own unique capabilities. Images are lifesize (unlike the "miniature" sized images from many boxes), those images appearing to not be attached to the speakers themselves. Drums are reproduced as from no other design imo (I’m a drummer), as are pianos. Singer’s voices are where the should be, about 5’ from the floor (that’s important to me; I listen to a lot of singing).
Electrostatic speakers are also planar dipoles, and do some things better than Maggies. They, generally speaking, possess greater liquid see through transparency and low-level resolution. But they too have their limitations---no bottom octave, limited maximum SPL, small sweet spot. And they are mostly more expensive than the 3.7i, around twice as much.
There is a magnetic-planar alternative to the 3.7i, one that requires less power and comes in a smaller package (5’ H, 13" W)---the Eminent Technology LFT-8b. It retails for less than half the price of the 3.7i ($2499/pr), has a midrange driver covering 180Hz to 10kHz with no crossover (!), an 8" sealed woofer for 180Hz down, and a ribbon tweeter for 10k up. It is an easy (mostly resistive) 8 ohm load, so tube amps like it. And it CAN be bi-amped. An under-appreciated bargain!