I love it... only thing I have been playing since release.
But saying that, it does have its flaws. Bits of it can be repetitive - go unlock safehouse, collect side missions, finish encounters, unlock next safe house, rinse and repeat... but it does get broken up by the story missions and if you are that way inclined, the Dark Zone.
All in all, I love the cover based mechanics, I love the co-op aspect of it and I love how tense the extractions are in the Dark Zone when you have some choice loot.
Thumbs up from me