Best tube rolling options for VAC Ren MkIII preamp


I have read most VAC threads on Audiogon and pieced together some information on tube rolling for VAC 300.1a and VAC preamps (Renaissance Mk III is what I own). Was hoping to get in one thread others' experience/POV/advice on what the best tube swapping options have been for their VAC gear, or other high end amps/preamps that take similar tubes (e.g., 12AX7, 12AU7, 6sn7), or if stock tubes from VAC ended up being the best choice. Thanks in advance for any insights. If I'm missing an definitive thread on this pls redirect me.
podeschi
My Recently added seimens 7308s into my Ren sig mk2a made a huge. Difference - deeper and tighter bass, more extended highs, etc. Overall a much better, well balanced sound. Wouldn't have believed it out of 2 tubes.

Added Black treasures as the front 4 tubes for each 300.1 about a year ago. Got slightly sweeter,more extended highs.

Good luck.
Hi Fplanner2010, I received mine and just installed them. I will share my results in time.
Great!! Although we have great VAC in common, our systems
Are quite a bit dissimilar since our speakers are so different. I heard a difference immediately, that has just kept getting better at about 40 hours so far.
Ok i clearly need to make a second run at this! I would let the amp warm up for an hour before critical listening but didnt burn in jan, ken rad etc input tubes. I will do that and give it a second listen. Part of my impatience was tied to others' comments how it was hard to beat vac stock tubes.
I should add...what i find hard to replicate is the open extended airy highs of stock 6sn7 tubes