As others have said, I also have a lot of photos of the same deer posing for photos one after the other with white flash cameras. The only thing I have noticed is that deer will sometimes move to another trail a few yards away. But that has only happened a few times in almost 5 years of running trail cams.
As a scouting tool, the IR's may be a good deal mainly for a theft deterrent. Although, if you are looking at the camera when it goes off, you can see a red glow.
I've had an IR cam for about a year and most of the time it sits around the house gathering dust. My white flash cams are out year round.
Here's a pic from my Leaf River IR.