I have both the Miracle and Dare collars for my horse. The Miracle collar would stop him, but it had to be so tight on him that it was leaving rubs even with the fleece covers; it also stretched out quite a bit over time and I had to keep moving to higher holes (which really confused some of the barn staff who didn't know which marking to use).
I originally got the Dare collar thinking I would swap between the two collars to keep any rubs from getting bad, but I haven't used the Miracle since I first swapped. The Dare hasn't left any rubs at all, and is easier to put on/off. I could leave it pretty loose at first, but then he figured out he could still crib if he tried hard enough. It probably also stretched a little, though not nearly as noticeably as the Miracle. Overall, I like it a lot more, and it's effective for my horse. Since you've already got it, you might as well give it a try.
If he's choosing to crib over eating, or cribs a lot while he's eating, it's a pretty sure sign of ulcers. I think I've already seen you post about that before (?) so I won't give you the rant on that
i'm moving to a new barn and they are concerned (even though it's been proven otherwise) that the horses in the barn with him will learn to crib from seeing him do it
It's pretty hard to convince people otherwise. One of the trainers at my barn has a TB mare who's 2 stalls down from a pony that cribs. Her horse recently found that she could pull on a loose piece of her feed tub and make a lot of noise; not cribbing, just playing with something with her mouth that makes a loud obnoxious sound. I overheard the trainer say that her horse better not be learning how to crib from the pony- mind you, her mare can't even see
the pony, so she'd have to learn just by hearing him grunt. When I commented that studies haven't shown any evidence that horses learn to crib from observing other horses do it, she just dismissed it because I have a horse who cribs, and therefore I must be biased.
It couldn't possibly be that I have a horse that cribs and therefore have a personal reason to really look into the latest research on causes, prevention and management of cribbers