I have Apogee Duetta signatures and Vienna Acoustics Beethoven. The Apogees did some things better, on the right recording they can launch a bass wave into the room that no box speaker can quite match. They are also slightly more transparent in the midrange but the VA's have a more detailed and airy treble. Overall the Vienna are more cosistently satisfying. I also have friend who was an acknowledged eletrostatic fan who had owned various models from Acoustat and Martin Login. Anyway he tried a pair of Vienna Acoustic Mahlers and was so happy he sold his ML Monoliths, a year later he got a pair of ML Prodigy's the VA's prevailed and the Prodigy's soon. About a year later he decided to try the ultimate stat the big ass Soundlabs and sold his Mahler's. Sometime later he calls me and asks me if I thought he was crazy because after living with the Soundlabs he had buyers remorse and whas thinking about buying another pair of VA Mahler's. I told him he wasn't crazy the Soundlabs were slightly more transparent but we both agreed that the VA's were just as coherent and seamless as the Soundlabs but had better bass, with superior imaging and soundstaging.
Anyway my Apogee's are in storage but sometimes I miss that wave launch. My friend has been cured of his panel addiction and still has the Mahlers with no plans of going back.