Toyo may own Nitto but, they are not the same tire. Different tread designs for sure. The Trail Grappler is a newer tire and I've heard good things from the people I've met who ran them. Having said this, I'll admit I'm a little gunshy with respect to Nitto tires in general because the TerraGrapplers I had on my old Dodge for a year were indeed, "squirmy." Truck felt like it was driving on slimmy, wet diapers in turns, even in dry weather. That was on 285/70R17s using the Dodge's stock wheels.
After 37,000miles, my Raptor's original tires are looking like they can afford to be replaced. I'm looking toward the Toyo Open Country M/T or Goodyear MT/R w/Kevlar if I don't stick with the stockers. The one point of concern is the extra weight of the Toyo and Nitto tires. You're looking at an extra 18-20lbs of unsprung weight in the tires. I can't help but wonder if that won't create additional wear and tear on the steering and suspension.
Ditto on the Nitto.. I've heard good things, but any M/T is gonna be noisier and ride harsher (sidewall), and the extra weight you will definitely feel. When I switched to Grabber Red Letters, they were stiffer and heavier. I like the look of the Toyo, but haven't got a set of either because I can't decide, lol. I'm thinking the Nitto Trails will be the next set on my 11 F250. The reviews I've read on forums and tire sites say they are quieter, but who the hell knows, right? The weight won't be noticeable on this truck, its gonna be a 35" tire is all.
I have reservations about the Goodyear MT/R Kevlar tires. I bought a set for my 09 F250 and Goodyear took em back at less 8,000 miles, they had used up 60% of their tread (the taller tread had leveled out with the shorter single tread in the middle)I think they are more suited for the Jeep crowd (lighter trucks) and heavy mud use. They have a cool tread pattern, but I think for day to day, its loud and wears too fast... just my opinion. Unsprung weight shouldn't have too much impact on the suspension, the suspension is holding up the truck, not the tires.