I found it really helpful. Towards transition and in second stage though, i wasn't sucking just biting on the mouthpiece. That was wht I really needed at that stage

I have had friends who can't use it, it amde them sick.

FWIW with my first I had the lot - gas, peth & epi - and with my second & third just gas - andthe gas was the best by far on every count.

Also I think a lot of it is 'head-stuff' - as mentioned in previous posts, it gives you something to focus on, well true for me anyway, and it was just enough to make me feel like I could continue coping as I was.

Good luck