Not great. Not even particularly good. But exciting enough to hold attention.
Some really dumb plot contrivances. Putting the Enterprise under water. Pretending Kirk was actually going to die. Trying to make us think Kahn wasn’t the “villain.” Building a super powerful military complex and then having Scotty be able to fly right into it without being questioned or stopped. And so forth.
Tried to make characters work. Tried to show us Kirk, Scotty and Spock develop. Some interesting moments for or between these characters.
Well filmed in that, unlike Man of Steel, you could always follow the action even when characters were moving super quickly.
An entertaining, but flawed action flick that would have done well to avoid the conveniences of “we need this to happen in order to tell the story we want” plot holes.