I just had one 2 weeks ago. I was not put out completely, they basically give you a valium and a rufie. The worst part is the colyte. The procedure itself is nothing. Also, if they know you have the apnea issues, they will give you O2 thru nasal pillows and the anesthesiologist will keep an eye on ya.

I am still in the "titration study" period, but the first mask I asked for was the nasal pillows because the idea of a mask covering my face freaked me out. I found that it just did not work for me, as if it was tight enough to keep the seal, it hurt like hell, and if it was loose enough not to hurt...