650 total spent on a direct bolt in. Welds look solid, like the counterweights (lets me know they balanced it) and love the idea of the snap ring U joints so I can actually service it 😂 As far as the aluminum vs carbon fiber debate...we used aluminum driveshafts on the helicopters i worked on in the corps. They held up very well at 1400+ RPMs. Carbon fiber I'm skeptical of because of things like delamination if any scrapes or nicks occur. Maybe i'm just talking out of my butt.