Classic Spider-Man Goodness!
Sometimes certain creators will just "get" a character. This is definitely the case here.
Writer Gerry Conway starts the tension of the story on the high setting and just ratchets it up from there, until the climax of the final page. This story is a perfect example of how to build a mood and suspense. We see how Tombstone's origins have lead the current situation to where it is today. Conway was firing on all cylinders during this period and it really shows.
Also adding to the drama and tension is the stellar artistry of Sal Buscema. From the menacing cover image, to the final panel of the last page, Sal's skills are as sharp and honed as I've ever seen them. All of this, while the focus of the tale isn't even on Spider-Man! The long run Conway and Buscema would have on this title is a high water mark for both creators and this issue is a prime example of just why that is.
This is just some excellent comic work here! A perfect example of how Spider-Man comics should be done!