Yeah, cos the Brazzers ones are basically embracing the "poor acting and lousy scripts in porn" joke and making it part of their schtick. So now fake acting is actually part of the feature now.
If you want good scripts and fairly decent acting, check out something like PureTaboo (as the name goes, expect more... dark stuff). Oh, and BellesaHouse has a series where the pornstars decide who they want to shoot with and the studio just plays matchmaker and provides a bed, so you get something a lot more authentic out of it.