I have owned ’57s since 1973 and recently had them rebuilt by Kent at Electrostatic Solutions. I’m now using my old Quad II amps with really good glass, instead of more powerful ARC tube amps in the 60-75 watt range and think they sound better with the little Quad amps- rated at what, 15 watts? You don’t need a lot of power to drive them, but the impedance curve is daunting for some amps.
As to whether they are better than your dynamic speaker system, why be forced to make a choice? I run two systems- when I’m in the mood for the Quads, I use them- when I want bigger, louder, more bass, I fire up my horn-based system (which also uses relatively low powered amps).
The old Quad is one of those speakers that people regret selling and buy again for pretty much the reason you explained. If you are ever in Austin, you can have a listen here to both. (Not a dealer). :)