I think the big changes with cooling were that people no longer care about actual 2 slot cards, everything needs 3 or 4 now, companies stopped with shrouds that covered up all of the fins so air could not escape, and we have good heat pipes now.with stamped fins on everything. Not to mention that the PCB are so much better now that you have to cool the VRM so you cannot get away with extruded crap.

The way cards boost now and OC them selves I think helps too since if you could run the same clock/power 5c cooler you get to move to another clock bin up and that shows in reviews.