I really liked it. Winters played a small-town Michigan detective whose police department was underfunded with outdated technology, so the FBI sets up a satellite office and sends in an agent (Duhamel) to work there and be partners with Winters. There is a lot of conflict between them, as Winters is more of a cynic who has hardly left his hometown, is blue-collar, and feels underappreciated in his work, while Duhamel is charming, handsome, liked by everyone, gets publicity when he solves a case, and drives Winters crazy with his vagueness about his past and his convenient lies about his backstory. Neither trust each other, and I liked watching the evolution as they both learned to work together, trust one another, and have a deeper understanding of one another, it felt really earned and worth it to watch.
It had a good ensemble cast. I liked seeing Janet McTeer as the assertive and caring police chief, Liza Lapira as a perceptive and intelligent cop, and Kal Penn as a mature and down to earth detective. There were some good guest appearances from Candice Bergin as an convicted con artist and Winters' mother; Robert Sean Leonard as a grieving father out for vengeance; Patton Oswalt as a party-boy mayor who gets nearly assassinated; and Bokeem Woodbine as a remorseless killer in a cold case.
The show even had a "will they or won't they" subplot with Winters and the office manager (Aubrey Dollar) being secretly attracted to each other, and denying their real feelings to just be platonic co-workers. Normally I don't like that trope, as it gets tedious (plus I thought the actors had too big of an age difference of 16 years that made it look less equal), but the show handled it well, and it ended up closing in a nice and less predictable way.
The show was a very good mix of comedy and drama, and would get dead serious at times, so much that I would forget about the comedic parts and be into the drama. I would say the humor and pace is like Castle, but it still felt like its own thing. I read an AV Club interview with Winters where he mentioned previous shows of his that got cancelled that he liked making (Life on Mars, Happy Town), and hoped that Battle Creek would last. Unfortunately, I don't think it was promoted much, and was easy to forget to watch.
I heard of Winters through Oz (I didn't see it when it aired, I had just heard of him as one of the breakout stars), and enjoying seeing him pop up in a lot of NYC-based TV shows (Law & Order, Sex & the City, Rescue Me, Brooklyn 99, 30 Rock), even if he almost always was a streetwise cynical asshole. I like his warm, cigarette-touched voice, and how he can be absolutely hilarious in giving straight delivery of self-centered, arrogant jerkoffs. He rarely plays a nice guy (Rescue Me was an exception), yet I found him totally likable anyway. He just seems like an awesome guy, and I like seeing him pop up in stuff as a reliable character actor.