Terminator 2 (T2) has long been my #1 favorite movie (circa 1992–2004). In recent years, my admiration of Cameron's work has continued to grow.
Then came T3, made without Cameron. T3 clearly was a mistake. It neglected most of the subtleties that T2 had in reference to T1—cross-references are a trademark of Cameron in all of his films—not to mention the countless discrepancies in the storyline, and the "cheap fixes" to do away with other key elements. It was a decent action movie, but it did not fit in the Terminator franchise.
Hence my enormous reluctance to watch this fourth instalment, which I feared was another T3. Now, 3.5 years after its release, I can conclude they have tried to compensate for the mistakes of T3. In fact, I would even say they overcompensated at times.
For example, they did the "face punch and recover" no less than three times. And what's up with the Schwarzenegger archive footage? Oh by the way, why didn't Skynet just kill Reese right away; they didn't do anything with him except lock him up. The film makers went out of their way to throw in as many references to T1/T2 as they possibly could, and my personal opinion is that they succeeded with that. The director also did a fine job recreating the feel of T1 and T2 in terms of filming style and angles.
Overall: great action, direction and CGI; good acting; okay soundtrack (not that memorable), but most of all a nice "connect the dots" for the old fans... which should have been part 3.