OK, so I run Registry Mechanic and CCleaner's registry scanning tool religiously, so I've always assumed my system registry was in pretty good shape.
Today I ran RegSeeker for the first time, right after finishing a combination of Registry Mechanic / CCleaner registry scans, and it found a whopping 1698 issues with my registry.
WTF.
How the hell is it able to find so much that the others didn't?