Yes, they had the very first X1/Grand Slamms according to Ed at CJ, who retired a few years ago,...and I have the photo of their listening room which had the newer Grand Slamms in it as well. Transparent Audio, CJ and Wilson Grand Slamms were one of a number of regular triumvirates at Wilson, CJ and Transparent in their respective listening rooms many years ago as I understand. Transparent now have the XLFs, but I don't know if they still have a CJ amp among the amps they have there.
Martin Colloms review of the Grand Slamm from many, many years ago, also had particularly positive things to say about the CJ Premier 12, Transparent Cable and the Grand Slamms.
That's right lose track of the Wilson speakers
Not sure about Transparent any more. Years ago when went to Transparent, it was cj, Krell and VTL. (Know they have the Doshi phono there now too