I went to Kamm, McKenzie, etc...with my twin pregnancy. But, I moved and ended up delivering in SC. They took excellent care of me while I was pregnant and would have stayed with them if I didn't move. They deliver at Wake Med.
I admit I do not know a lot about twin pregnancies. Our first was born at 32 weeks and so I was high risk with our second. The NICU (level 4) at Wake Med Raleigh is the best (according to all the docs and specialists I spoke with) and so we went with Kamm, McKenzie, et al. for my second pregnancy b/c they deliver at Wake Med Raleigh. So if there is an increased chance of NICU time (preterm labor, etc.), I'd recommend Kamm et al. for Wake Med Raleigh.
Re: best place to deliver twins in the triangle?