Only the obvious differences. Open sights on the Trackers, D/T'd for scope on the Ultras and no open sights. And, of course the difference in the thickness of the barrels. Which translates to the weight of the gun and felt recoil. I think the rates of twist are the same in the Trackers as in the Ultra. Those who have both say the accuracy is about the same. If you are sittin in a stand the weight isn't that big a deal, but if your style is more "scoot n shoot" then you may want to opt for the Tracker. I was fortunate to get a Tracker I smooth bore sighted barrel when the factory still had them. The cheapest slugger to shoot. I have it in 20ga and really like it.
cookiemann