"If evryone took oneobgyn's approach to this hobby, nobody would learn anything on this forum"
That is a laughable comment. I have probably done more tube rolling in my 40 years in this hobby than you can imagine. I have a friend who also has a Ref 3 and has rolled just about every tube imagineable. When all was said and done his analysis was similar to mine. All you are doing is creating a different "flavor", most far from euphonic and many with tube bloom. I am not saying "don't experiment". I am saying that I have been there and done that. BTW, I am surprised that none of you have tried KT 88's of different manufacturers in place of the 6550.
I have always asked myself when I change a piece of equipment or roll a tube, "am I hearing something different, or am I hearing something better?" That is what experience has taught me. But heck, that is just me.