A racket usually comes in 2 versions: 3U and 4U versions, or lately 4U and 5U. Just wondering for those who have both the heavier and lighter versions, what specific differences did you find between 2 versions. Victor: Some on BC report that the difference is only in the wooden handle - the 4U has a hole made with a slightly bigger drill. This means the carbon mould (head + shaft) is essential the same. In my experience (tried 3U4U Braveswords, MX's), the balance was a total crapshoot, sometimes even the 4U had a higher balance point than the 3U sometimes. But the interesting thing is, for the most part, the 4U counterpart always played a bit more flexible than the 3U. So I'm suspecting, could they be using a softer grade shaft for the 4U's, or perhaps a shaft with a more hollowed center? Li ning: I haven't tried Yonex: Tried an Armortec 700 (original) 3U and 4U. From the few times I've tried them, the extra weight seemed to be more evenly distributed to head, shaft, and handle. Because the head-heaviness and overall balance felt similar, but the racket felt heavier. Stiffness was similar, but the power shots felt more solid, possibly due to more material on the head.