[drivebyubnt]

I'd be careful about giving too much credit to the original ARM design. In retrospect, like many early RISC designs, it was over-optimised for its original application. Most of the unique/novel features of the original ARM architecture turned out to be bad ideas in the long run. Most of them were later removed from the architecture, or persist only in backwards compatibility modes.

ARM is ubiquitous today more due to business models and historical accident than to inherent superiority of the design. (See also x86.)

[kragen]

That's interesting! Clearly that's what happened to packing the PSW into the PC†, but what other features are you thinking of?

† though there are an awful lot of ARM processors out there today that have less than 64 MiB of program memory and need their interrupts to be fast, so I'd argue it might be a reasonable idea for many applications today if it didn't involve breaking toolchain compatibility in a subtle way