Dare I try to offer an explanation of why some perceive R2R to sound better than the source when a vinyl or CD is put to tape.
I think it's about the lens at which we listen to music. R2R, like vinyl, takes a tiny signal and blows it up onto a big canvas (or at least it does with good machines/preamp circuits). It makes everything lifesize.
The fact that the lion's share of recorded music before say 1990 was originally committed to tape in the first place might mean that getting the music back on the original "canvas" type can put everything closer in place to the original recording.
The perspective of tape and vinyl, I think, is what makes some people perceive it to be more pleasing than digital. That can happen despite noise.
With regard to the sub master reel tapes made from the original masters or safety masters (e.g. Chad Kassem's work, Tape Project, etc.), it does seem that most listeners find them to be very present, clear, and musical.
Currently, I'm rolling Oscar Petersen's "We Get Requests" in 15ips. My EQ is set at NAB, which is incorrect for this recording. I haven't had the opportunity to address changing the resistors on the playback board for CCIR/IEC2 equalization yet. Guess what? It's stupendous.
While I certainly agree there's tiny amount of 15ips reel-to-reel recordings out there that we can easily access, those that are out there give me hope that we will see more and more added. If I could get 15 recordings in each of the big genres (say jazz, rock, folk, country, etc.) and those recordings were classics (think Waltz for Debby, Dark Side of the Moon, Willie Nelson/Waylon Jennings, and so on) I'd say this is a worthwhile exercise.
Tape sounds present, large, dynamic, powerful, clean and lovely. If done right it takes you there. I have no issue committing time and resources to it. Frankly, I think high quality tape has shown me (subjectively) I'm better off playing in tape than buying "better components" over and over.