Planars/ Electrostats benefits over box speakers?

I always been fascinated by Martin Logan and Magneplanar speakers. I have heard one or two models of both over the years. Would like to get some input from owners of "planar speakers" as what sound quality benefits do they offer over a floorstander, especially in the area of overall smoothness.

Are there any planar models of either company that have a small footprint and are not monolithic in height, but still sound very good???