@magnetic
If I may ask.. what will you be using it for?
I ask because I'm still vaguely considering porting my catweasel.device to AmigaOS 3 (should be quite simple as it has AOS4, AROS and MorphOS support already), if it would be of any use to people. The official one is probably a bit faster but I believe mine supports RAWRead better, and it supports different formats. Plus it's open source.
If you're only going to use it for Amiga and 3.5" PC disks, you're probably better off with the official one.
Edit: incidentally, my GUI-based disk imager already supports the official multidisk.device, if it's any use (but there's no publically available build of it for 3.x at the moment - but I can make one)....