Characters wander in and out of the story with little logic, the Dominion plot line just kind of trails off, and all of Starfleet vs Starbase 1 was kind of silly.
But Shaw is an amazing character, Vadic is fun to watch, the TNG crew got a far better send off than Nemesis, and the acting is fantastic. The fanservice of seeing the Ro, Shelby, Moriarty, and the E-D again was also fantastic as someone who grew up watching TNG with my dad.
The season has problems, but I love it anyway.
Jack getting into Starfleet and assigned to a ship so fast can be easily explained with Starfleet being low on people after the events of the show. Also, he's still an ensign, so he didn't get jumped through the ranks. His bridge position is also something that Seven gave him as a special assignment rather than a standard bridge position specifically because of his background. He's essentially a formalized version of Mariner's role on the Ceritos.