Well. Even the pi 1 is vastly faster than even the fastest Acorn workstation.

The two major flies in the ointment are that RISC OS has never had a wifi stack (use ethernet or an external wireless access point) and that some of the old software hasn't survived the shift from the ARM2/3's 26-bit addressing mode to the more modern 32-bit standard. But if you don't have old games you want to be nostalgic about, that's less of a problem!

[OP/article author here]

RISC OS recently changed ownership and it is now fully open-source. The new owners have sponsored an improved version with more bundled software, called RISC OS Direct: https://www.riscosdev.com/direct/

Perfect use-case, I have repurposed a RPi 3 for RISCOS with an old DVI monitor connected via an HDMI to DVI converter. Now it sits in my workshop as an "internet terminal". Ideal for looking up data sheets and pinouts for connectors etc.

Works very well on a RP3B. Support for the RP4 is not yet complete.