You're right overall that most of these places are a lot less flashy on the inside (have worked at a couple). Linear models everywhere as you said
However I think you're underestimating RenTech here. They're genuinely just in another league compared to what most people consider the "elite" quant shops. You're not getting in unless you're an actually impressive academic with a track-record, so I wouldn't be surprised if they're trying some weird stuff that other shops can't even understand (although I would imagine in small size vs. more vanilla stuff).
IMO places like JS/CitSec do a really good job of bombarding campuses to inculcate this idea they're the absolute apex of mathematical wizardry, but the places that are really doing some dark magic shit aren't trying to get undergrads to apply to them. Ofc maybe I'm falling for the same kind of propaganda for RenTech
However I think you're underestimating RenTech here. They're genuinely just in another league compared to what most people consider the "elite" quant shops. You're not getting in unless you're an actually impressive academic with a track-record, so I wouldn't be surprised if they're trying some weird stuff that other shops can't even understand (although I would imagine in small size vs. more vanilla stuff).
IMO places like JS/CitSec do a really good job of bombarding campuses to inculcate this idea they're the absolute apex of mathematical wizardry, but the places that are really doing some dark magic shit aren't trying to get undergrads to apply to them. Ofc maybe I'm falling for the same kind of propaganda for RenTech