i also recommend the ztto-type bbs from alix, with 2 pieces of alu sleeve that screw into each other. if your frame has good tolerances, it's awesome, and costs c.12 eur.
it must be stiffer than the shimano version, which, as we understand it, exists to be forgiving with bad manufacturing.
in spirit, the ztto thing is a hambini bb, because once you've screwed the 2 bits together, you have a solid alu sleeves across the frame. That's got to be stiffer than 2 plastic cups that barely connect with a piece of plastic.
it's the sort of thing that's incredibly impractical to test, but take an aethos-like bike, which physically looks like a pool noodle, and run stiffness tests with a shimano BB and that ztto BB. I'd be curious, but there's got to be a difference, right? Also, there may not be. But for 12 eur, me likey.