I picked up Walking Dead Season pass from the PS store last night and have had the same problem. I've plenty of hard drive space (70/120gb), I'm going to try formatting and doing a database rebuild tonight to see if it fixes the issues.
The stuttering is annoying, but it's essentially unplayable when it freezes so long that I can't make a choice and then someone is upset with Lee for doing nothing. The other issue has been when the audio skips so much that I don't actually know what the character said and then I'm forced to choose a response and hope for the best. I find it only stutters when it's saving, but it's saving CONSTANTLY.
I will definitely send a video if I continue to experience issues, since I hummed and haaa'd over deciding to grab it for the PS3/Xbox/PC/iPad, and am choked that I seem to have made the wrong choice!!