Anyone basing decisions on Payscale data doesn’t understand Payscale and how awful it is as an unbiased source of data. It is all self-reported and is therefore not a representative sample of a given school’s graduates. It also does nothing to control for cost of living. Stevens graduates are heavily represented in the NYC area, for example, so their salaries will sjew very high but that doesn’t mean that their purchasing power will be any greater than an Iowa State graduate with a lower salary living in St. Louis (for example, since I know Boeing hires a ton of Iowa State graduates). The point here is not to say the graduates of either school are superior or inferior to one another, but rather that salary is a terrible indicator of such things, and the salary data from sites like Payscale are a poor indicator of salary anyway.
Regarding the process of weeding out students, I think it is dramatically overblown. Very few schools (if any) actively try to weed out good students. Most, in a moment of candor over a beer, would probably admit that weeding out some students (specifically the ones that simply aren’t prepared or motivated enough to handle the material) is a good thing. However, most if not all schools nationwide actively attempt to improve attrition rates. State schools also often have dramatically higher attrition than private schools because their public-school missions generally mean less selective admissions regardless of the strengths of their programs. The bottom line is that no school is going to try to “weed out” an otherwise good student. No school really actively tries to weed out anyone these days. It just happens for various reasons.
Finally, @eyemgh alluded to my opinion on the value of graduate research to undergraduate programs, but I think he underestimated how strongly I feel that way. In most cases, I think a strong graduate research program is a very positive thing for the undergraduates at a school. Professors who are up to date with the cutting edge of their field are better able to use relevant, modern examples and incorporate their experiences as researchers into their curriculum. The presence of strong research programs also typically means there are undergraduate research opportunities to be had should a student want to do that, which can be very beneficial to students who choose to do so.
All of the schools on this list have a good reputation and they are all at least reasonably active in research. I’m a little surprised there is so much hand wringing and argument over this (though I’m not really surprised given this is CC). There probably isn’t a wrong choice here, though I’m honestly a little surprised that @MonsterCrwu chose Stevens given how enamored they seemed with ISU.