Ok, so I watched it and can answer this question for myself, and hopefully for others...

It is basically a blow by blow, hour by hour retelling of the Boston Bombings. I'm not informed enough to be able to judge its accuracy, but it doesn't feel gratuitous in any way. It's a very human presentation - focused on the community reaction, and the strength of people in Boston in the wake of the attack, and the police officers and security officials who worked to find the guys afterwards. There are definitely moments when they go off on one banging the drum for America and freedom, and the flavour of patriotism is a bit intense, but under the circumstances, it's kind of forgivable, and it doesn't detract much as a viewer.

Bit long, and it feels a bit too soon to be making it, but overall pretty solid film I reckon.

Glad to hear it. Walberg was also in Deepwater Horizon. Seems to be the go-to guy for "Too soon" movies. :)