Mishimoto is not a “high-end” radiator. It’s a solid unit built the way it should be and better than what you can get at the auto parts stores for sure. And the number one thing, it’s not some cheap multi core aluminum knock of radiator that isn’t worth the aluminum they used to build it. After you fight heating issues over and over and literally chase your own tail trying every “fix” and throwing a lot of money at the issue, a $400 radiator is nothing. I have personally discovered the hard way that most of cooling system “upgrades” are a gimmick. The Mishimoto is not.
Next step above a mishimoto would be a Novak imho. ColdCase may merit a strong look as well. The old 3” core Griffith JeepSpeed radiator was probably the best core out there. I will say though, that mishimoto can handle quiet a beating. And the lifetime warranty is pretty sweet