I don't have a ton of experience with this sort of thing, but it seems likely that it's not so much a stopping power issue as it might be adjustment and wear. I have the cheapo shimano with cheapo pads, alu rims, and if it's adjusted and not too worn I can stop a lot faster than I can... not fall of the bike? So I'd say, start by getting some better pads and recabling them, oiling the cables when you do.