Really? I prefer TNG. This may be a generational thing. I find it's 90's style optimism easier to relate to than the cold war liberalism of TOS, because it's more familiar to me. I also find the acting better. Certainly, Patrick Stewart is a better actor than William Shatner.
But... about the characters themselves.... Picard is some sort of non-INTP NT, while original series Kirk is some sort of Se dom. (yes, even within the show itself, he's just older and more mature. Look at the original crop of movies, he hates being out of the action, doesn't believe in no-win scenarios, etc.)
Picard seems to be more interested in being an explorer and a discover than Kirk. Kirk seemed to like being a starship captain because it was an opportunity to be a man of action. Being an NT myself, I relate to the former more, as well as the crotchetiness.
The fifties and the sixties were the golden age of science fiction, and that is reflected in the accuracy and intellectualism of the TOS scenari.
And no, William Shatner is not a worst actor than Patrick Stewart. He's much more vivid and even sometimes abrasive, always eager to make snarky comments. Considering the limited budget and the cheap sceneries they had during TOS, they all were incredible actors to make their stories "believable".
And in TOS, Kirk is not especially "a man of action". He's the ultimate leader, always balancing every extreme under his command, always reactive, and that's different. And that's why he has to seduce every side of the issue. If you look more carefully, he almost never disobeyed direct orders, he just spent his time trying a way to understand them in a slightly more efficient way. I'd say you're confusing the Kirk from TOS and the Kirk from recent movies.
Picard, in comparison, is much more conservative and careful , and he always does what is expected from him. He's the classic, predictable senior leader. He's the boring fatherhood figure a teenager serie would direly need.
