The only other competitor chipset for AMD is Via, and that chipset absolutely sucks. If you are referring to intel chipsets, it's a given you'll get more clock speed out of the Intel, but you'd have to OC like 800MHz-1GHz on an Intel which would be like 400MHz-600MHz on an AMD.
I'm running 236MHz 1:1 ratio 472FSB on a socket A system...nforce2 chipset...you can get 250+ if you have 2x256 but I have a 1gb kit.
I don't know what kind of research you mean, but saying 'an nforce chipset wont OC as well as other chipsets' without pointing out exactly what chipsets you're referring to is pretty vague and for the most part not true