Hi billy,
You're quite right on the meaning of "hybrid". The Martin Logan (and many electrostatics) use a conventional dynamic woofer for the deep bass, because electrostatic panels cannot reproduce deep bass at loud levels without "arcing", which would damage the membrane diaphragm.
You've also noted some of the other typical limitations of electrostatics--having to be positioned perfectly to get a reasonable stereo image, and the "laid-back" quality, which usually means a somewhat recessed midrange. But lots of listeners like that quality.
I think you'd find the M60s more forgiving in terms of placement--a few inches out from the wall behind is all that's required--and much more detailed in the midrange than the Martin-Logans. But planar speakers of all stripes are always interesting to experiment with.
The 5-ohm impedance is likely marginal for your Sony. It probably doesn't like it but I doubt it would trigger any current limiting unless the impedance curve dipped lower.
