T3 started to focus too much on john connor (played by a bad actor given bad lines) and was just ridiculous i.e forced humor (glasses scene). The female lead in t3 was tosh. She was a model but couldn't act. Showing a frowning face is not akin to good acting and can't be considered anywhere near the role robert patrick played as the t1000 where there was real menace. Basically the problem with the movies are cameron didn't direct them.
I disagree somewhat. T2 focused way too much on John. The franchise is called "Terminator". It should be about the Terminators and what they do. Instead, it became about John and how he only survives because of Terminators??? WTF happened here? I think Cameron ^^^^ed it up himself. T3 and TS are what we are left with after Cameron wiped his ass with his own concept.
T-1000 had presence, but the T-X was the second most machine-like to me. As for frowning, Robert Patrick did that all over T2