I have had no problems since upgrading to Windows 10 last week.
I'm running Windows 10 Pro with Mixcontrol 3.6 downloaded from the Saffire Pro 40 location (although I'm using the Pro 14). The OHCI scan tool reports this:
Looking for OHCI 1394 Host Controllers...
1:
Vendor : (1106) VIA Technologies
Chipset: (3044) VT6307/VT6308
Revision: C0
Status : Active
Details:
Subsysten VendorId: 1043
Subsystem DeviceId: 81fe
Max # isoch Rx contexts: 4
Max # isoch Tx contexts: 8
Max 1394 Speed Capability: S400
Support: Compatible, no known issues.
Done.