I'm someone who thinks "That Which Survives" deserves its bad rep. I would rate it bottom 5 TOS for many reasons.
I'm not sure about bottom 5, but That Which Survives
does deserve its bad reputation.
However, the scene with Scotty in the crawlway is cool in a nerdgasmy kind of way. And, That Which Survives
is a good source of "canon fodder" and other trivia, such as for how fast the Enterprise
can go, and in showing that you can move a little and see things while beaming. Also, it's the second time Catwoman was in Star Trek.
* - Although, it's at least the third Catwoman/Star Trek
connection, with different "Catwomen" too, because Eartha Kitt's Kitty Car was in Bread and Circuses,
which miraculously gets us back to the OP episode [linky