Reason for optimism: Regression, inevitable after the 35-win improvement over two seasons, set in, and yet the Astros were still contenders.
Reason for pessimism: For two years running their cross-state foes have kept them at bay with Hogwarts-like dark magic -- and as active as the front office was, they didn't sign an Auror.
The Astros repeated a material weakness on offense in 2016 that didn't allow them to achieve their lofty playoff expectations. Rather than repeat myself verbatim, take a look at last year's projection because it reads like a crystal ball, and the problem, a mildly improving but still bottom-tier offense in terms of batting average and on-base percentage, did them in. The Astros merely hit a lot of home runs last year (198 in 2016, 14th in the majors) instead of a ton in 2015 (230 in 2015, 2nd most), and it couldn't mask their other offensive shortcomings.
Houston's front office did not address this deficiency in the 2015 offseason, but they certainly did this year.