I had problems with using it in DOS, but that was a system without a PnP manager. However, it was the only PnP card on the system, which apparently, shouldn't have been an issue. Doom engine notably wasn't generating midi on it.
The card was discussed a little on a thread started by me a few years ago:
Roland SC-88VL Hookup
But in truth, that thread is really about the SC-88VL
All around, my feeling is that the Super-MPU-IIAT is a card for systems of the mid-nineties, when it was released. At first, I thought I wouldn't be able to use it, but ultimately I built a Pentium system Windows 3.1 as its primary OS, and have been well pleased. Probably good for Windows 95 as well, but a pure Dos system? I was displeased...
This is just my experience, though.