T bone,
Get that dvd by the Grimmets, it explains in great detail how to judge antelope. I think its called size is everything.
The only down side to the video is that most of the bucks they use as reference are so damn big, anyone would see they're record book size. But, the scoring system they use is very good. I wish they had more bucks in the 78-82 range as thats when they get difficult to judge IMO.
Personally, what I look for is prong and mass first. I dont worry about length all that much. That being said, I've never killed anything that net scored over 78, but I have shot a few in that size class.
I think when bucks reach 78+ they get darn difficult to judge above that and even tougher to pass up. I think when you see a buck that has it all...mass, prong, and length you'll know it. The tough part is when a buck has say great mass, a good prong, but not much length or good length good prong, but not real massive.
Good luck judging them things...after a while they all start looking the same.