I've used the collagen casings from Sausage Maker several times.
I don't have problems with them blowing out. They work well and are really easy to use. But they don't twist tie. You have to tie them off with butcher twine (unless I'm doing something wrong). That can be tedious. They also don't roll / bend as easily. I find the fresh ones a good thickness. The smoked ones are a little too thick when bitten into. I think these might be better in some respects, but worse in others... I'm not sure because I haven't used natural yet, but have some in my fridge for next time.