If you are going to compare Bitdefender free with IObit Malware Fighter then it should be IObit Malware Fighter Free or compare IObit Malwarefighter Pro to Bitdefender Antivirus Plus(Paid) version.
Either way it is Bitdefender hands down.
When you compare both paid versions there is really no difference in "functionality" other than an auto clean feature in IObit which can be achieved by CCleaner which is free and contains other useful tools.
IObit Malware Fighter also uses Bitdefenders engine.
If you are thinking of purchasing one of these products I would consider Bitdefender.
Personally I would spend the $10 extra dollars for Bitdefender.
I guess he is serious, I thought I was going to get here and it was a joke.
Honestly, you could compare IObit's whole fleet and BitDefender will win
hands down, 100% of the time They make some good tools but in the
security world they have many many miles to travel before they can stand
with the likes of BitDefender
Iobit Pro is paid and uses Bitdefender technology, but I do not know how this technology is well implemented.
However, my vote goes to Bitdefender free, without a doubt, the original one for free, what we also want ?