I recently migrated from a 32-bit XP machine with two HDD's to a 64-bit W7 machine with three HDD's. I have been, and am currently running, 8.5. I haven't loaded X1 yet.
Migrating Sonar wasn't too much trouble and has been covered above. I have lots of screenshots of my old setup to prove it.
However, the 64-bit W7 versions of some VST's expect their resource and sample libraries to reside in different places, and make it very difficult to locate the resources where I want them to be.
Dim Pro can be remapped fairly easily by editing the registry. However, Rapture does not provide that option, and a query to Sonar Technical support (who I typically find provides very timely response) pretty much said "too bad for me" about relocating the Rapture resources. In this case, I have to maintain two identical copies of the samples directory: one in the hard-coded location for the factory patches, and one in a location that my own programs can reference.
I simply don't understand why I can't locate the instrument resources and samples where I want them. My gripes about Caakewalk would be non-existent if it wasn't for this primitive implementation.