DL vs. Fast Track Sympathetic Stimulation

I always have believed, through my readings and lectures, that the greatest sympathetic stimulation is with the direct laryngoscopy, ("cold steal is the real deal"). My classmate begs to differ, and says the most stimulation is from the ETT passing thru and being settled in the vocal cords. This topic came up in discussion because of the fast track LMA, in which there is no actual DL, and therefore, I thought NO (or little) sympathetic stimulation. What do you think, and do you know of any research articles related to this topic?

My theory was the Fast Track was a great way to intubate fragile cardiac patients b/c of the lack of DL stimulation. I may be way off.