Sorry Nicholas, I should have been more clear. I've used RiscOS a number of times, but not for long enough to know it terrifically well. Most of the Acorn systems I ever fiddled around with were essentially "collectors" pieces, as no one I knew over here ever really had one back in the day.
Functionally I found it to be a lot of fun, but not something I would enjoy using on any regular basis. More of a personal taste issue, I just found the GUI ugly in all sorts of ungodly ways, lol.
We didn't see a heck of a lot of RiscOS/Acorn systems over here in North America, so I always saw the GUI visually offputting.