^ About 35 minutes for the whole process (all automated).
You can't run the fix on a RAID array. So if you have a RAID array you'll need to split the RAID before running the fix, run the fix on the single drives, and then rebuild the RAID array.
stage 1 updates the firmware.
stage 2 to 4 restores the speed.
No need to remove the data on a single drive before running the fix. Just make sure you have a backup of the data.