Answer: pretty slow. The last two days - yes, it's that slow, granted I wasn't doing the tests 24/7 - I've run Bonnie I/O benchmarks on the Amiga UNIX box. Since these results are incomplete, I don't think it's worth a forum thread but maybe it's still interesting to some people.
The complete results for Amix 2.1c are located here
. Here's a summary though. Apologies for screwing up the layout if you have a low res display, but it's my damn blog :-)