Being stiffer, the fast flight kind of material will have more higher frequency harmonics than the dacron. The character of the harmonics will vary depending on the specifics of the material, and to some degree, the string construction. If you use silencers, and they're placed well, this need not be an issue. Also, much of the string noise is often the string slapping against the limb after the shot. Sidp from Border Bows clued in to laying a 3/4 inch piece of soft side velcro, centered where the string leaves the limb when braced. Totally removes any buzz.
Then again, my wife's montana was incredibly quiet with a dacron string, albeit with heavy arrows, and not so fast either. Ultimately, went with fast flight plus with otter fur balls, and it is just as quiet.
Either will work. I prefer a modern material myself, given the option, as i like the feel, and I prefer to have more of the energy that I put. Into the bow make it into the arrow, all else being equal, or capable of being made so (because if you get down to the details, all else is never equal) but any material is capable of shooting better than we can.