Cary v12 using different output tubes

Has anyone tried using 6550's or KT88's with the V12,
and if so what were the pro's and con's of the change
compared to the stock EL34?
I auditioned a V12 with KT88 tubes. I never heard it with the EL34. I just LOVE Cary equipment and own 3 of their amps and 1 preamp, but thought the KT88 tubes in this amp sounded not to my taste. My thoughts based on my ears, I would stick to the EL34 in this amp.