Using gw12.0.3 Stand alone gwcheck
I copied a user Archive to my local HD ran gwcheck with only Structure and Fix and User,Message options..
After 24 Hrs it did not complete the Checking Blob Files portion.
I restarted again with all options selected, after 30 hrs it seems to be sitting there, doing nothing.
The last log item displayed is "Checking Blob files for validity. This is a Large Archive and contains 540,000 files
the Archive Folder is 45Gb.