I do not use it but know several who do, it is ok as an additional layer of security defense along side your AV program and good programs like Malwarebytes and superantispyware. What it does is use several antivirus programs to scan if anything malicious is found.
the scans are free but I think to use the clean feature you have to pay.
Never hurts to do one more extra scan.It is not a real time scanner just scans when you choose to do one.

This is info about which of the Antivirus programs it uses when it does the scan on malware found.

"Hitman Pro's antivirus brain trust consists of G Data, ESET's NOD32, Avira AntiVir, Prevx, and a-squared. If any unknown suspicious files remain after this step, Hitman Pro compresses them and securely uploads them for direct analysis by the scan cloud team."

I use it when I do virus removal on other peoples computers remotely. It has consistantly found rootkits/bootkits that SuperAntiSpyware & Mbam have not.

It will send programs it doesnt have in its data base home for them to look at... without asking! Not quite a good idea to me, .. you may or may not have a chance to cancel those uploads, to do so you have to sit and watch it run and have good eyes. It does a very quick scan.. very few minutes.

It has a checkbox for one time use only on first run.. after that it will scan & report but not remove the bad guys, unless you purchase the program.

I give it a big saved me time & headaches thanks, for way too many times ...on too many computers.

Think I would skip any free 'protection' it might offer. Unless I purchased it first.