What is the performance penalty of using RansomWhere.app? As many might be aware OS X is now potential victim of ransomware exploits.  So far we have one example only, First Mac-targeting ransom ware hits Transmission users, researchers say, but chances are that these exploits will increase.

I recently read about RansomWhere.app that might be effective in protecting your mac from ransom ware attacks, by monitoring the file system for the creation of encrypted files (and blocking the process doing the encryption).  My understanding is that the developer(s) of this program are highly qualified and whatnot but (and here is the questions):

Does anyone use this program?  What is the performance penalty?

I ask because I have multiple redundant backups, so a ransom ware attack would force me to wipe my disk and use one of my backups (losing a day or less of files at most)?  Multiple redundant backups are needed anyway, so what is the net advantage of using ransomware defeating software?
I have used it for the past few weeks on my 12" Retina MacBook and noticed no impact on performance.