I've still got my original DrDos 6 bundle. Box is a bit tatty now. Got Novell Dos 7 at some point though haven't used that yet. Already Have IBM Dos 5.0 at least one box still sealed. IMSs Real/32 is an interesting beast being a multi user Dos with a Concurrent Dos heritage. There is an option to install as single user if you wanted. The version I've got is ment to support Fat32 and built-in zip100/ls120 drive support in the kernal I believe.
The Acorn x86s processor cards for the RiscPCs I aquired came with IBM Dos 6.3. Quite a neat setup and hard case seeing MS Windows 3.x running under RiscOS.
Ever give the Dos China Union version of MS Dos 7 a shot at all? Totally illegal and you're totally evil for using it of course
Kinda made sense if you were not into Windows. It's nice FreeDos is about and has an active following but really from what I gather that really is for more modern hardware.
The Acorn never falls far from the tree.. x86 GUI whore.