FWIW, I have been looking for a different setup with my RF97A. I just strung two of them with Lux 16g gut mains and BBO Rough crosses at 55/53. I had previously strung it with a FB of BBO Rough at 46, a FB of ProLine X at 48, a FB of ALU Power Ltd Ruby at 50, a FB of ALU Power Ltd Purple at 48, and a FB of Laserfibre JB Tour 100 at 50.
Proline X and JB Tour we’re far superior for consistency and control over the other FB poly setups.
I also strung one frame with NXT Max 15 at 58.
Strung bed firmness between all of these setups was actually VERY similar
NXT FB has the most power by a smidge. Followed closely by JB Tour 100, ALU Ruby, then BBO Rough, and the least power but best control from PLX. I think BBO would offer less power if strung at same tension as PLX.
I usually break multi’s in about 90 minutes and polys last me about 10 hours.
Surprisingly, I have about 5 hours on the NXT Max and have found it to be the more arm friendly of these setups with the best sweet spot. I am losing a little bit of spin and depth control, however, and so I won’t stick with it if I can get the Gut/poly combo to work.
Lux gut/BBO Rough is VERY good. Control is second only to PLX. Very different string bed feel. Much more feedback about how well I have hit each shot, and depth control is as good as PLX. Funny thing, though, sweet spot feels more defined, slightly smaller, and one or crosses lower in the stringbed. This may be the result of more feedback and being able to differentiate better, but the markings on the strings from balls show that I am hitting more toward the center with this setup. I usually hit 2 crosses up and 2 crosses over from center with FB poly (I hit heavy topspin with SW grip). Spin is equal to PLX and more than the other setups. My arm is definitely less fatigued with gut/poly setup, but still feel some strain the next day. I may try 52/50on the next go-round.
So far, best comfort has come from slick, round, and very stiff poly at a fairly low tension, multi at higher tension, and gut/poly at mid tension. Ultimately, the feel is FAR superior with the gut/poly setup. So, I will probably stay with that.
Your mileage may vary, though.