My reasoning for recommending a fast twist, is that I've been down the "I'm building a gun for some specialized use" road....and later found out I wanted to use it for other stuff. But I couldn't. Because it was twisted too slow to play with other bullets. Same could be said for building too heavy of a rifle, or a number of other factors. No sense pigeonholing oneself.
I've shot fast twist 243s, 223s,and 223 AIs side by side with slower twist versions of same. Every one of them shot the same loads, to VERY similar velocities, with accuracy similar to what each rifle was capable of with any other loads.
The jacket shedding issue isn't really an issue, unless one insists on using archaic bullet designs. As barrels get really rough, it may crop up...but I haven't had any issues with a number of rifles shooting Ballistic Tips, even after a metric schit ton of rounds fired.
If one is looking for benchrest grade accuracy, sure, go with a twist that exactly matches your bullet. But you'd better be building a benchrest rifle, and have benchrest skills to be able to see a difference.
For real world use, I have yet to see a reason to limit myself on twist.
