I have ML ESLs, and I've used them with Rotel, Parasound, Conrad-Johnson Sonographe, some Chinese class D's, and Hafler. The ESL are extremely crisp and clean in the high end and the only amp that diminished that was the Parasound (it was a low end Parasound, though).
Every box speaker I've ever heard adds coloration to the sound of a snare drum or male voices, and the dome tweeters on them just don't match the transparency of the ML's.
I might suggest you raise the back end of your speakers so that the electrostatic panel is perpendicular to the floor. I think you'll find that the speakers character changes dramatically, and may be more of what you're looking for.