I just put a very fast graphics card into my dual core Pentium machine (nvidia gtx460). With this card Champions should fly, but... it doesn't. It does run with almost perfect graphics and sound, but performance is less than stellar. With the games graphics settings at roughly mid level I can run with minor jerkiness, but I should be getting much much better framerates than this.
BTW, I see Star Trek Online is officially supported. If so, you might want to consider making Champions Online official too, since they are basically the same engine, so what works for one should work for the other. Did I read something about performance problems on Star Trek Online as well? That would make sense, since they both run on the same engine; so any performance improvements in one should help in the other too.