I haven't picked it up, but I grilled a friend of mine who's been playing it nonstop since it came out.
It's mostly more of the same as MechWarrior 5 Mercenaries, but with a better story at the cost of the campaign being more linear.
IT's probably worth a pickup if you liked the last one, with the exception that if you liked the last one for the freewheeling campaign and just taking on contracts, you might not like this one.
The friendly AI has been ever so slightly improved with the UI for giving them commands being much better this time around.
As for the story, it's supposed to be pretty good full of tons of the old lore of the Battletech universe. You play as part of Smoke Jaguar one of the clans returning to the inner sphere to reclaim it.
In the end they got beat up by a telecom company, so how good could they have been really?