I have the DHS Fang Bo B2X:, 91.3g, 1442Hz. 6.1mm, and the Yinhe 970xx-A, 89g, 1291Hz 5.8mm-thick. The B2X is supposedly a little faster than the B2 although based on this review there are other differences. The B2X has a Limba outer layer, the 970xx-A has Koto. I am finding (with the same...