They work well enough for me and great for the price. Make sure you have your time set correctly or it will not use the IR properly. It is a little slower on the trigger than some of the high dollar cameras but I'm okay with that.
I have used several trail cameras, Truth Cam 46 is a one of it. It's good that it's simple to program, fast triggering and nice design. It's one of my favorite camera. I usually choose a new from http://www.bestsellingreviews.com/Sport/Trail-Camera/, providing reviews of several cams that provide good photo quality.