The Blue and the Black are neck-and-neck, for me, in the 'prettiest frame of the last few years' sweepstakes. If they were going to have them out only for a year or so, I sort of wish they'd waited, introduced the dual cores at launch, and used those paint jobs. I'm usually happier with older frames, but these days it's the X-Dual Platinum 99 (a slightly more flexible prototype of it that never made it to market, to be precise) that gets the call. As someone mentioned upthread, "slab of rubber" is not an inaccurate description of its feel. It is The Anti-Hollow. I too like the gut/poly hybrid, but I haven't given up on finding a (very) soft full-bed poly I like even better. I sometimes think the Pro One probably feels even better, but for some reason I really like the feel of the X-Dual's thin beam in the hand, and I probably need the extra little bit of spin window, too. (If I hadn't already thrown in my lot with the Plat 99's, and if my elbow tendons were any stronger, I'd be looking with interest at the Pro One OS. The blogger over at Guts & Glory – can't link; sorry – certainly seemed happy with it.) The two highest-ranked players at the academy where I teach are sisters; one plays the Pro One 16x19, the other the Gold 99.