I immediately turned it off as soon as I realized what it was doing when I was searching for media based on creation / modification date. I don’t want to alter the original files in any way. Having Premiere Pro write to the files is a really bad idea and in my opinion and I think it should have been set to ‘off’ by default. For an app that touts itself as working with native files I really don’t understand why they set this.
I would understand maybe if the Premiere Pro media management was stellar and it needed to track the files by adding metadata to them, but it is really better to track it all in companion files. Really though Premiere Pro’s media management is actually quite terrible even with their metadata system so it’s not helping.
There are other utilities for FCP’s horrid media management (though still better than Premiere Pro’s), such as those by Intelligent Assistant, which I believe does something similar and it can help you recover from a media management mess but really, NLE’s should just track the files using some other method that makes them unique, such as original creation date and time, and some type of checksum on the file size and content to make sure they match your database.
It did affect things for me negatively before I turned it off. Whenever I use PPro on a new machine I immediately turn it off before it messes with the original media.
I have not seen any adverse effects from turning it off though I suppose if you move the original media around a lot having it all in one place *might* help. Though I have no evidence of that.
My 2 cents.
-Keith