I agree with most points in here except:

Pretty cool right? You can picture her lips parting to scream, taste that delicious xeno-slaughter. Now here's what I run into too goddamn often... the same scene, but told instead of shown

This is obviously the show and tell rule. however, I feel that, once one has an understanding of the rule, it can be broken in favor of pacing. A lot of writers, especially newer ones, never think of pacing their stories. It's kind of the reason why you get stories that are Durdle fest or others that have ten things happen in one chapter.

It's one of the more subtle, but important things in writing a good story.

When i say well paced story, I do not mean "Oh a lot of action happened" Or "oh a lot of drama happened." I mean: Set up, Build up, Execution and climax, Pay off and resolution. This is basic but obscure part of writing, but can be learned.

Every scene, story, plot and so on has a beginning, middle, and ending. A conflict, and a resolution. A situation must be presented to the characters or the Characters must create the situation ( the second is by far better, but explained later). The situation must challenge or conflict with the character, and the character must have no choice but to confront it.

Notice how I did not say main character, because in a perfect world EVERY character should have a conflict and resolution.

So, how does this relate to pacing? Simple, Put each conflict, build up, and resolution in sync with each other. So, that character growth happens with each character in a small ways over a long period of time. And that's pacing for you. Sure you can speed up and get someone's development over with but remember a good character develops not only in big events but over time as well.

In general, pacing comes from developing the character and the plot. If you don't have enough development in a chapter, try and add more 'events' or 'character moments' in a story.

That's my two cents on that matter.