I agree that some of Mac.World's assumptions are a stretch, but I think what he was trying to point out is that you are assuming that ICS on a multi-core machine will be... what? More fluid than Prime with Honeycomb? That will be a safe bet. More fluid than iPad2 on iOS5? We won't know until we see it, but it could happen. More fluid than iPad3? Well, in that case, we are compairing an unknown hardware/software combination against a known hardware/untested software combination, and all bets are off.
I'm not saying the prime will be more fluid than the iPad at all, just that the benchmarks are already beating it and will only beat it even more so when the multi core enhancements come into play.
I have no doubt that android ics would be slower than iOS5 on the same hardware...android apps are written in java.