My understanding of vaccuum vs forceps is like someone else mentioned, just what that particular person is more comfortable with. I of course was not thrilled with either one, but I'd rather have whichever one the OB is used to, because that means it's less likely to have user error...at least in my head.
Like I said, while I'd rather not have either one performed, during my VBAC, I did have forceps used and I was very willing to allow the doctor to use them after 2 1/2 hours of pushing. I just wanted to make sure I got my VBAC!
Now that I have my confidence in myself and my body after having a VBAC, I'd really like to not have either. But at the time of my VBAC, the success of a VBAC was my main goal, not necessarily as much as how we got there. Sure, I wanted the dream birth, but I also wanted my VBAC, not a repeat c/s!
Not to say I'd just consent, just because the doctor wants to....it would be situational and I would like to discuss with the doctor ahead of time, especially since it bothers you and you have concerns.
I'd want to know in what cases s/he uses the vaccuum. And get in to details about things like, do you have a "time limit" with pushing! The time limit got to me with my DS. 2 hours of pushing and my OB was not liking that...so, she made me feel like I had to have a c/s! My VBAC, after an hour and a half of pushing (new OB), he started talking epidural, moving rooms, forceps and so on....I consented because I wanted this baby out, before he talked c/s!!!!!! So...I've switched OB's yet again, because this OB will let a mama push!!!! He said, "some women just take longer and you may be one of them!" The day I met with him he told me how he pushed with a woman for 4 hours the other week and that was just fine by him...she needed the time, that was just how her body and that baby were! So, he will not put me on the clock! So with him, I really feel like he's the kind of doctor that will only intervene if "I" want it, or if it's really necessary! If your doctor is more like that, I'd be comfortable with the vaccuum. Or, if you're comfortable with "just get me my VBAC" than that's one thing too!