I wheeled with a guy for a couple years that had a set of Trxus tires on an almost identical 4Runner to mine (we were both the same year/model, locked rear, open front, 285/75/16, same lift, shocks, nearly identical weights, different color). I rode with him numerous times but never drove. I was always impressed with them. Good road manners and great performance in the snow. For pressure we ran them down into the single digits in snow and low double digits on everything else and never had a sidewall or bead issue. Good in pretty much anything. I have no first hand experience with the longevity but he ran them for a couple of years. I almost bought a set for myself after wheeling with him so many times but ultimately decided on something else.
As far as Interco, they are a rock solid company who makes great products. Everyone runs Interco out here. When people complain about them usually they forget that Super Swampers and boggers are not made for the street. They will ride poorly compared to an all terrain tire. They will, however, excel offroad. Here in the northeast the Swamper is THE offroad tire for dedicated rigs. Out on a trail ride with the hard/extreme group and you will find swampers 5 to 1 over other tires (made up statistic, but this is my best guess). They do well in our terrain but you have to know the positives and negatives of anything you buy and a lot of people try to find the magic tire that will do 100% of what they need 100% of the time.
I think that the two tires listed are suited for different purposes. Terra grapplers will be better on the street. Trxus will win hands down off road. It all depends on the intended purpose. Swampers work well out here but probably fail miserably in Utah. Trxus is a good all around offroad tire that will see street time. The Terra Grappler is a great street tire that will see dry offroad trails. Define the intended use and you can start to narrow down tread patterns.
Edit: You just defined your use in the last post. Terra Grapplers might be decent. Im running a set of 37x13.5 Toyo Open Countrys. Ive run them in different sizes before and they do well in most situations. Not the best in snow but decent everywhere else. Not great, but decent. Im not familiar with other brands avaialable in that size to suggest. I'm a very big fan of the ******** Cepek FCII but have no first hand experience with sidewall durability, which would be a concern in your planned terrain. They are awesome in the snow.