Good Question!

If you can get good arrow flight, say out to 40 yds or so with Fixed heads, why change?? I have not tried the quickspins, but my guess is that due to increased weights and drag your arrows are going to lose speed and energy much quicker than say a straight fletch setup. For me, I want the flattest trajectory possible so that for hunting purposes exact yardage estimation is less critical. I shoot a 73 lb. 29" draw Hoyt Ultratec, acc 3-60's with 100 gr. thunderheads, and 4" straight vanes. With proper tuning I can use 1 pin out to 30 yards with tight groups all the way to 50 yards like darts. If I can get that, so can you, and if you can, why would you want to slow the whole operation down with heavy spiralling veins?
BTW, I like what I see in the Crossfire also. Good luck with the veins!