Difference between Conrad Johnson CT6 & ET3 preamp

Can anyone tell me the difference between the Conrad Johnson CT-6 and the ET3 preamps? I know the CT6 offers Theater mode, but I would be using this in a 2-channel set up with a SS McIntosh amp. Any info would be helpful.
The CT6 is based on the ART circuit and uses 4 6922 tubes. The ET3 is based on the newer GAT circuit and uses 1 6922 tube.

I haven't heard either and I think you would have to listen to them to determine which you prefer. c-j amps seem to be getting more "neutral" with each generation based on what I read.