This bolt is great, it allows to lower the cocking pressure and has an open face for good flow. The bolt is very light and smooth and puts up very little resistance to cycling.
There really isn't anything bad about it because it is light and smooth, all of which it claims to be. It may be exoensive if you dont like spending money but in paintball there has to be money spent to get the good stuff.
Overall this product is worth it and if you like to have your cycling pressure very low this is a good produt to get.