There is no direct comparison from any of the scans in 4.8 Quick, Standard or Thorough to the 5.0 Full scan, so you can't really compare. As Tech mentions you would have to create a custom scan to match the settings in the 4.8 scan that you did.
Then there is the Persistent and Temporary caches used to speed up scans and this would make a difference in speed, but should report the same number of files. That however, wouldn't really make a difference until you have run a couple of scans and reboots, etc.