I think PI should be maximum 15 yards unless it is absolutely egregious. If you pull a guy down to the ground before the ball gets there because you are beat then ok make it spot of the foul but some of these are so ticky tacky. I like the current rule that if you hold a guy before the ball is in the air its 5 yards. Then I think if the ball is in the air and it is minimal contact it should be a minor PI penalty which is up to 15 yards. So, it would be spot of the foul under 15 yards and 15 yards if the pass was beyond 15 yards. Then there should be a major PI penalty (think like in hockey when a defender trips a guy on a break away and they award a penalty shot). If this occurs it should be spot of the ball. You still need the threat of a spot of the ball foul otherwise guys are going to just tackle receivers on deep passes knowing it's only 15 yards.