VTL's and KT88's?

Howdy! Does anyone have any experience using KT88's in their VTL amps? Specifically, I have a pair of MB450 Signature (pre Series II version). The best current KT88 (Gold Lion) is reputed to provide better sound quality than the best current 6550C and I'm tempted to try them. At $900 for the two octets, I'd like to hear from anyone who's used KT88's in their VTL's before I take the plunge.

Thanks!