Yeah, that was the problem with T3, the lack of haracter development when compared to T2. When the T-850 said about the T-800 of T2, "That vos a different T-101," I felt like groaning out loud. I didn't get the trilogy on DVD until later - so viewing T3 for the first time was when I first understood that Ahnold Schwartznegger was playing a DIFFERENT character in each film and the T-800 had been my favourite character in T2. The T-800's development is cool and funny, but the T-850 never varies.
I did prefer the T-800's attempt at smiling to the T-850's shoplifting crack. As Ahnold says, "I look like an 'orse, trying to smile."