Personally, I have not used Biomex. I have been using mostly Geneza gear for some time now and some HG gear. I found something that I know works well and I know what to expect. I like the consistency of the very thin oil and the hack of injection pain I experience. I figure, if something isn't broke, don't try to fix it. So if I had to recommend one over the other, I would have to go with GP, just because that is what I am familiar with. Personally, I don't think you can go wrong with them. They've been making gear for some time and it has consistently worked the way I expected it to, for a few years now