For what it's worth.....
I can remember back in the 90s virtually all muskie "bucktails" (I'm talking about in-line spinner lures here) were tied with actual bucktail. The consensus was that natural bucktail was unmatched for this application in that it had the best combination of movement in the water etc. All my old bucktails I built/tied from those days were deer hair.
In the last several years, however, the trend among gear guys is definitely toward flashy synthetics in bucktail spinners. There are still a lot of deer hair in spinners but many of the most popular blade baits now are entirely synthetic. They cast well, shed water, push water, and really have a nice flashy aspect.
Not sure how much of this is relevant to actual muskie flies.....but some food for thought.