A couple of months ago, I purchased two Apple PC 5.25" drives on eBay along with the hard-to-find (but necessary) NuBus controller card for the Mac II series. I had several threads showing my progress in getting the PC drive to work with System 7.1 on my IIfx to view PC/DOS documents from my Commodore PC-10 III in addition to SoftWindows 1.0.2. All of those threads were unfortunately deleted during the recent site crash.
The consensus was the 5.25" drive works better in System 6 - Apple File Exchange was sometimes buggy in System 7.1 and would hang the IIfx when transferring data from a well-known working DOS disk. As for SoftWindows, it would recognize the 5.25" drive in both DOS and Windows 3.1, but would not load or install programs from any of my DOS disks (I would get an error message). This was likely due to the 5.25" drive not being officially supported by SoftWindows. According to the owner's manual, only a handful of 5.25" drives are supported, one of them being DaynaFile's own concoction. Currently on the lookout for a working DaynaFile drive.