I own both models in question, 14.5 ultra light and 14.5 light contour JP rifles. Both rifles are set up identical. On the bench the light contour out shines the ultra light due to easier to hold. The ultra light is capable of great groups, but not it’s main objective. Carry rifle, hunting rifle and love it for hoser type match. I shoot it out to 400 yards with 4 power scope no issues on steel. I find my self grabbing the ultra light more when hunting or as a ranch gun. Both guns are great! For shooting matches, I would use the ultra for shorter range type matches and light for matches with greater distance because it is easier to hold or lock into position.
Both have JP heat disapators and have not experience any heating issues during practice. I hardly ever use my 18 inch light model unless my goal is shooting long range since I have purchased these two rifles.
hope this helps, cannot go wrong with either.