Production-wise, absolutely nothing changed. It's all passable but decent at best, including the CGI used for the (quite infrequent) action cuts during the baseball games, mainly Bonda's pitching. Even more telling is the fact that both the OP and ED have been recycled from the first season, albeit with different visuals. Now both of the songs are quite nice, but it goes to show that Gurazeni doesn't exactly have any resources to spare. Anyone making it past the first season will likely not mind that too much, but don't expect improvements.
That being said, story-wise Gurazeni only got better. While the first season perfectly got by with workplace slice-of-life, the second season builds on that and gives some payoff, though without any excessive fanfare or drama. Most characters from the first season make a return to build on their previous appearances, and usually they go a little deeper into the specific topic, usually regarding their future as athletes. Special notion should go to Yuki, Bonda's love interest that took up the entirety of season 1's ED despite only appearing in the final episode. This time around she's got a far larger role, and her perspective as an outsider is even cleverly used against Bonda's insider look a few times. On top of that she is cute as all hell.
In truth, Gurazeni season 2 really is just more of the same. It's a realistic look at the lives of athletes operating within a giant mechanism called baseball, with specific attention towards the monetary goals of it's cogs. It's neither overly optimistic or too cynical, and ultimately gets by on the down-to-earth and likeable cast. In a landscape filled with stories in which the athletes are heroes and their sport nothing less than their life, Gurazeni is absolutely a fresh, almost unique anime.