In many ways the Category model is broken, mixing the 5's with 4's is just one example. Category 5 is supposed to be for racers to learn the craft, but its just treated like any other race.

My last race was a technical crit, corners no wider than 6 feet, and no way people can go into them with any speed or do any passing. Our race probably had at least 5 people racing for the first time. There was no briefing about the corners, or any other pre race advisories (holding lines, crossing wheels)...just a whistle. So what happens? 2 guys end up in the hospital because they go into the corner too fast and cross wheels.

Not everyone learns the craft prior to going to a race. Some guys just buy a bike, and go to a race, they have no clue about pack safety, and the Cat 5 format only really ensures these guys only endanger other Cat 5's. USAC could do some things better that would make it useful, (puts on flamesuit) but its treated like any other race.

I guess what I'm trying to say is, Cat 5 is pointless in its current model.