The different types of commercial and DIY ESL's present different loads to an amplifier.
While true in a general sense an ESL presents a capacitive load.
Given that P = Voltage * Current * cos(phase difference between the 2).
Assumming we are dealing with voltage amps with low R
out that means that the amplifier needs to be able to deliver significant current despite the cap load.
You will not find a specification for this but you are usually ;ooking for something with a significantly beefy power supply.
I have not used ESLs in a long time, but back when we were selling Dayton-Wrights, the big boys (lots of 200+ w amps coming out at the time) did not do the job well, the surprise was that teh NAIM 250 drove them, even a set in parallel, seemingly with ease.
You are looking for an amplifier that can deliver lots of extra current.
dave