Hmmm. I used System Profiler, but that didn't ship until MacOS 7.6…
I can't remember this for definite, but I think there were some memory differences. Was the Modern Memory Manager PowerPC only? If so, if it's present in the memory control panel, you're on PPC. Also, I believe on PowerPC, the suggested memory allocation of apps is smaller when virtual memory is turned on, compared to when it is turned off… but I can't remember if this only applies to native apps or if it's all of them.
Sorry I can't be of more help, I'm trying to remember this stuff from years ago
Amy
P.S., here's me using my 540c to present a talk at NSScotland:
