Saw this over on NeoGaf:
So Chris Carter aka @DtoidChris just posted this a few minutes ago on his twitter feed.
"I beat Dead Rising 3 twice, and only once did I have any framerate problems for a few seconds -- and it didn't impede my gameplay at all."
Also I asked about in co-op and was told "no noticable difference" Yes, Yes, YES!!!!
http://www.neogaf.com/forum/showpost.php?p=90412391&postcount=681