“The Pro Version is [not as fast] as the free version... and Malwarebytes still finds some malware [in some distributions].” Reddit · r/antivirus · 5 years ago Pro vs. Ultimate: Which to Choose?
“Occasionally on program boot, I could hear the read/write head on my hard drive chattering—not a sound you want to hear... frequent enough to be disconcerting.” PCWorld · 12 years ago
The software merges scattered bits of empty space into large contiguous blocks, which helps prevent the fragmentation of newly created files. Community Perspectives User Experiences & Reliability
Some users have reported more critical feedback regarding its impact on hardware and the inclusion of additional software.
Both versions are known for their high-speed "proprietary defragmentation technology," which can often process a standard hard drive in under 10 minutes.
“It’s worth installing the free version first to see how you'll get on with it. It's a very small installation, but it has plenty of features... definitely worth the money if you're trying to get as much performance as possible.” myReviewer.com Performance & Concerns