The 32 bit boards all are using different processors. Whereas all the 8 bit boards were using the same atmega 2560 running at 16mhz the 32 bit boards range from 72mhz all the way up to 300mhz. The higher the clock speed of the processor can only translate into more decisions made per second. And so you would think we would all be searching for the 32 bit board with the best processor because that will very likely handle the higher speed printing in the best capacity. The most powerful 32 bit mainboard we can get by the specs right now outside of the DUET 3 6HC which runs at 300mhz is gonna be the FYSETC S6 which runs at 180mhz. Here is a link to this board on ali: S6 V2.0 Board 32 Bit Control Board Support 6X TMC Drivers Uart/SPI Flying Wire XH/MX Connector VS F6 V1.3 SKR V1.3|3D Printer Parts & Accessories| - AliExpress .
The SKR mini e3 runs at 72mhz, The SKR 1.3 and 1.4 run at 100mhz, The SKR 1.4 Turbo runs at 120mhz, The SKR PRO and GTR 1.0 run at 168mhz. All 8 bit boards were near identical apart from their connectors But the 32 bit boards are a completely different world. They are all different.