Buffer time is definitely the episode where I stopped doubting they knew how to handle trek.
Interesting, I almost gave up on the show after the buffer time episode. Watching a Starfleet captain create a timesheet-obsessed toxic work environment made it seem like the show would be too much "The Office in space".
I'm glad I gave it a little more time, though, it definitely picks up for me after the first half-season or so.
Kirk never turned evil! He just got into an ego-driven power struggle with his old ship's captain, almost derailing a vital mission to save Earth. Then he authorised the creation of a doomsday weapon, which he left unguarded and undefended. Then he tried to fix that mistake by rushing over with a training ship full of cadets, only to get attacked by another old mistake he never kept tabs on. Then he stole that same ship...
I'm kind of dubious that this particular happenstance was intentional, but it's worth noting that Roddenberry was actively queer baiting in the accompanying novelization...
There are two kinds of TOS episodes: the ones that are so historically great you absolutely have to watch them, and the ones that are so iconically bad that you absolutely must experience them.
Season 3 is the most polished, but also chokes with hyper nostalgic pandering. Sadly every season has major issues for me.