I liked Nick Stahl as John Connor better than Edward Furlong. I also lean more toward liking the third movie better than the second. It always made sense to me, that if judgement day didn't happened back in 1997, John Connor would go through life as a loser, for fear that anything he did could put him back on the radar and perhaps bring about the end of the world.
Terminator 3 does a good job of illustrating how judgment day is inevitable when SkyNet sends the terminator back to kill John's generals, (who didn't know to stay under the radar) and introduce the SkyNet virus, instead. It showed how judgment day wasn't dependent on John's membership in society or any particular computer that he or his mother might destroy.