My preference is „bare metal” approach, then I really know if everything is working as it should, so I had a separate drive for Linux installation at the beginning and got to my other drives by just mounting them as NTFS.

But, finally I am at the point of no return for some time now, the old Windows drive is not even inside of my PC and the other drives are ext4 already.

For a quick check Live CDs/USBs are totally fine but not fully representative.