If you're writing PC disks you'll have trouble writing 1.2MB ones - they need HD drives which spin at 360rpm instead of the Amiga's 300rpm, as well as using the 28.8MHz clock.
If you want to read/write lots of disk formats, then you need OS4 and a Catweasel really, it's the best solution. I know this because I've spent much of the last year writing the drivers for it.

My webpage is
http://www.retroreview.com/iang/Catweasel/ if you're interested.
If it helps, I've also got it mostly working under AROS, and soon MorphOS. I've been tempted to do a OS 3.1 build too, but that'd take a bit more time, and is less necessary as the original Catweasel drivers work ok for the most part.