I own the same speakers, driven by an Accuphase E470 integrated (a good match IMO), and the sound I'm experimenting is definitely not anemic either, despite the fact that Accuphase is not a brand renowned for stunning dynamics. So:
1. I have the PKB kit (microphone for Anthem ARC room correction) and don't like what it does to the music. Bass gets too light, rounded and lacking punch, even the midrange seems to inexplicably lose some of the wonderful immediacy of the electrostatics. Tinkering with the software made for some improvements, but not enough. I'd skip the built in room correction and play a bit with the deep pass potentiometers in the back of the speakers. The +/- 2dB at 150 (200?) Hz switch was also better left untouched in my case.
2. I'm also using the speakers close to the back wall (back of the speakers is at the minimum manufacturer approved distance to the back wall, i.e. 20 cm), but that is the long wall in my case.
3. Do experiment with those drapes! You want that some of that back wave absorbed and some of it dispersed. This is hugely important! In fact, the whole room acoustics is always important but it is essential with the electrostatics IME. What I'm about to say will raise some eyebrows but trust me, I'm not making this claim lightly: the room treatments / acoustics are in this case much more important than the amplifier used! I've spent countless hours tinkering with the room. The back firing bass driver should aim at the bare wall while the panel should "see" thick absorbing material, but NOT covering the whole back wall etc. Experimenting is the way.
4. These are picky and revealing speakers. All the other components of your system should have good synergy with them, not only the amplifiers - the cables and power outlets (I'd avoid anything with silver or with rhodium plating), the source (I'm using a rich sounding Accuphase CD/SACD player / DAC, I'm not sure your CChord isn't too clinical for the Logans...) etc. My dealer repeatedly said that a matching source is even more important that a matching amplifier for these speakers.
Good luck and keep us posted!