I've used them. They are a little pickier about stuffing and by your description you're overstuffing them for the capacity of collagen casing.
Make sure you prick every air bubble with a pin to bleed out the air. And when you cook, some fork sized holes poked in the sausage help it relieve pressure while cooking though you do lose some juiciness.
Overall, I prefer natural casing. Much easier to work with, but trickier to store.
Phil |