I feel they built up Miguel as an apprentice that got too big for his britches, that was the first time that they delved into the Dex has a friend that he can trust and kill with angle. But you're right, Prado being arguably the coolest/most powerful character in the show's history going out in a whimper was anti-climactic. But it set up GWK being on Dexter's tail because he was led to believe he knew Freebo's whereabouts and Ramon the no-nonsense dogged detective SGT being next in line for a piece of Dexter's ass was really good so I can't complain.
My personal favorite season after the first because of Dex and Miguel's relationships and the subtle shyt they'd say to allude to the true nature of their dealings. Like when Rita and Syl said they should go get massages then Dex says, IDK, being on a table naked and helpless, that doesn't sound like fun.
And Miguel wanting to bring Ramon in on their secret only for Dex to bat the bee's nest that was Ramon and get Miguel to trust him more than his own brother was so ill.
Plus it was the first time it seemed like Dexter was a vigilante weapon because of the times Miguel did the detective work for Dexter to do the job.
It's funny because over time Dex has turned into Miguel, sloppy and increasingly brazen, not to mention sooner or later coming to the realization that LaGuerta is getting too close.
This season is a lot like three with certain plot points.
Deb trying to enlist Dexter to kill people. Hannah being someone he can trust and confide in. He and Louis's back and forth being much like his and Ramon's etc.
And he was the DA, crazy crazy season.