Power tubes for the VAC 300.1

I'm the proud owner of a VAC 300.1A stereo amplifier. I'm thinking of changing the 8 KT88 power tubes to Gold Lion. According to the manual they claim buying the tubes from VAC is prefered over using other brands. Has anyone else here used alternate tubes rather than the VAC branded tubes in their 300.1?
Hi Chris, there was a pretty good thread associated with the Sigma160i a few weeks ago about VAC and current production KT88 tubes.