In fact I have also tried the bow from Fiddleman, that bow is a little bit heavier, but the response is not good, I play it for two years (not often), the hair suddenly broken one day I performance (...!)

However, if you are professional player, this bow is too light, and the response is not so good like other cheaper bows; if you wish to play difficult songs, you need to find some other ways overcome the response problem, such as you have to hold it more gently and play more gently to get a good response; if you play fast, the bow is like flying but not jumping very well; you need to find another feeling to get everything work (imagine you are holding lighter version of bow, and it could work much better)