I mentioned once years ago, to my friend Terry Wegmann, that I was looking to get 2 of my most favorite kits of all time--the Bill Gould 4-course tank cars. I told him that I was only going to purchase kits boxed and sold as Gould kits, as I felt that the parts cast and offered for sale from Tichy to have been cycled more times than earlier runs and was troubled about parts quality. I was half expecting Terry to give me his "are you crazy" response but Terry was in full agreement with my reasoning.
He mentioned an extreme example of later shots from tooling suffering over time was the Cal Scale plastic AB brake set. He said that the mold face of the two tool sides would degrade enough that flashing was getting too severe. Cal Scale's solution was to surface grind the meeting faces to solve the flashing. This repair was apparently done more than once, and Terry said that he could identify what generation of brake shots he looked at by how far from cylindrical the air reservoir component deviated.
So to me both Intermountain and Red Caboose kits should be better in the older color printed boxes than the later non-colored boxed kits. Though I have to admit I often can't see any real differences in these two brands of new vs. older.