I have the free version, therefore I must perform a manual threat scan. Before performing the scan, I check the update status. If it says "Current", I start the scan.
My complaint is that even though the update status is current, the first thing the scan does is to perform an update check, which seems to take forever. It is redundant and a waste of my time.
Doesn't the program know that it is already up-to-date? After all, it just told me so!
Otherwise, Malwarebytes performs well and I have no other complaints. The scans are fairly quick and the interface is easy to use. It has caught several potentially dangerous items, and I use it in conjunction with AVG Antivirus. There has never been any conflict between the two.