You are right in that there should be a best but there are way to many variables. I have heard the GL 88's called the best, not in my book, they sound great, but so do my other tubes I have put through the hoops of my amps.
I know what you are referring about when you stated that there should be some information about the "best". There are many posts claiming that the GL 88's are the best, I bit and purchased a quad and they do sound good, but in my system, I cannot proclaim as the best. I truly believe that the TAD's I had years ago may have held that honor in my system. But if genrally speaking if many people state such and such a product is great and the general consensus is that it is a good product, then in all regards that product must have some merit. I have bought stuff based on this mentality and the results have generally been great, but there will be letdowns. That is why it is such a system and individual dependant issue and not really the consensus of the audiohood. If the reports state that some tube works great and later on you learn that it does not work on your system well, does it make that tube bad? No.
If there is one thing I have learned in this hobby is that there is no subsitiute for your own ears. I would at least purchase a set of the tubes you want allow and for break-in and validate the sound for yourself.
For what it is worth, I have posted the same question about the GL tubes and that is why I am referring you to try and validate for yourself. Feedback from someone who has the same amps as you do would be great. There are people who own the same amps I do, sadly, they either speak Japanese or German. From what I have learned from the German forums, it seems like a tossup between the GL's and other brands for the Octave amps.
Good luck,
Audioquest4life