Any broadhead (vented or not) is going to generate noise. One thing to consider is that the noise we hear as the arrow is leaving us is going to sound vastly different on the receiving end of the broadhead (in both frequency and amplitude). If you're really curious, setup your phone to record audio next to your target. Then compare the noise a field point makes vs a montec vs a spitfire. I have a sneaking suspicion that the difference (assumming a properly tuned bow) is going to be relatively negligible.
I've shot montecs in the past and had good luck with them. There have been countless deer harvested every year with montecs with no problems. This year I'm experimenting with solid one piece single bevels, but if I have to fall back on a broadhead it'll be my montecs. I say shoot what works best for you and don't sweat the small stuff