RE: fixed blades for SPEED?
It is not impossible and if your set-up is correct, it is down right easy! I shoot fixed blades only! I use the Montec G5, 100 grain, with my Mathews LX, 68 lbs, 30 inch, 29 inch arrow @ 289 fps. I can screw on a broadhead or a field point and group without touching my sights.