Maddow is awful, as Daily Howler points out over and over. She's a child in a grownup seat, never managing to take the news she's pimping seriously, always going for the gags. Perfect foil for Trump.

Jack Shafer in saying he is okay with what she did, basically speaks quite well for me on her major downsides:

[....] So why am I fine with Maddow’s tax-story grandstanding? Oh, I could do without the maddening community theater dramatics she brings to every show—the eye-rolling, the sarcasm, the faux earnestness, the annoyingly conversational style that assumes that you’re a passenger on her news bus. But there’s a long sensationalist tradition in American journalism of using a 400-ton metal stamping machine to extract every drop of juice out of an important scoop, then grinding the remaining pulp and feeding those tailings to the audience.

Unlike your standard bad sensational news story, Maddow’s puffed-up piece contained no mention of sex, no bloody murder, no crime and no violated social norm. She took a timely story of great importance—do we have evidence that Trump is a tax cheat?—and answered it. Well, answered it repeatedly in the negative, but I don’t hold the repetition against her, either. If Trump appears to have been on the level when it comes to his 2005 taxes, that’s good to know, even if you don’t like him.

I’m even fine with all of Maddow and Johnston’s heavy conjecture about how Trump’s 2005 tax return might fit into the Russia puzzle, or should I say question, of whether he’s captive of Russian oligarchs.  As the late Timesman Tom Wicker once wrote, and I can’t stop repeating, a little speculation can help unstick a political story from the mire and move it to realms where new proof can be gathered, and the story advanced. [....]

I especially don't cotton to the "passenger on her news bus" thing, because it's just like Limbaugh: lecture, lecture, lecture with mega drama added....she is much more palatable when she has guests to interview. It's the drama queen thing I guess bothers me the most, as Lawrence O'Donnell lecturing on his show doesn't turn me off in the least.