You'd have thought *someone* at one of the major hardware sites would have done this one, at least out of curiosity. I suspect that everyone went straight to the Celeron 566 because of the greater overclocking potential (though my 533A is running at 920MHz at 1.85v ) I checked those sites that cdrakejr listed, and no one has reviewed a 533A FC-PGA processor - only the PPGA chips.
There was a benchmark of both the Celeron 533 and 533A at an Asian site (either Singapore or Japan) right before the Coppermine Celerons were introduced. The results - at 533MHz, the Mendocino and Coppermine cores performed virtually identically except for benchmarks that used SSE (like 3DMark2000), where the Coppermine core clobbered the Mendocino. The results were pretty much what one would expect, which is why I didn't bookmark the link.
If you want to know what the Celeron 2 is slow relative to the Pentium III, search the forums for the rather extensive previous discussions about cache size, latency and associativity. It's only slow relative to something else. I can tell you 920MHz is pretty decent.