[Bartweiss]

It's a weird mix, because some of the jokes were pretty intricate and clever. The background stuff (e.g. writing on whiteboards) is also correct; a bunch of it is apparently equations pulled from old physics papers.

The characterizations, meanwhile... well, Howard and Sheldon both struck me as pointlessly mean-spirited portrayals, while Rajesh was just a really overwrought stereotype. It felt like the technical side of things ended at input on specific jokes, and in response everything else was hammed up to ensure it would maintain mass appeal.

Of course, that's a pretty common pattern - could-be-good works getting diluted to ensure they won't drive away any viewers. I wouldn't be surprised if it boils down to a good idea plus executive meddling. The later seasons also seem to have a really bad case of Flanderization, where writing novel jokes got hard so "hah, nerdy talk!" came to the fore.