They have done it and we have seen it a million times before, I mean, what else were you thinking!
Seriously though, would you think Apple or any other company could have a successful product launch by saying "we barely catch up with the competition", it should be obvious for anyone reading this site that performance figures shown by own manufacturers (no matter who) are unreliable and not meant to be taken seriously... having that said...
ExtremeTech has a detailed report on how benchmarks were conducted for the G5 vs. Intel CPUs comparison, a third party was contracted and a widely known benchmarking suite was used BUT everything went by Apple's rules. Like I said yesterday, "could outperform any Windows-based PC on the market" is a bold enough statement - 'true' is not a requirement.