It definitely has some pros, but the strong cons make it a no-go for me. I'd recommend the story of it more as something to watch than something to play.

The effects work seen in-engine is some of the best I've seen in an RTS. Watching debris from a freshly-destroyed ghost careen forward with the momentum that the ghost had right before it exploded, with purple flame streaking behind the debris, is awesome.

Certain super units, when engaged with opposing forces, are just a sight to behold, because of the superb effects work.

The game has two art styles:

One seen in the cutscenes (arguably the best that Halo has looked since the Bungie days; not absolutely everything that you see in the cutscenes is the best version of visual design of something in Halo, but a lot of it is; fantastic work, Blur), and then one seen in the game itself. The in-game art style should be familiar to anyone who has played the tablet games, Spartan Assault and Spartan Strike. I really don't like the more stylized looks to the environments, especially the rocks and Forerunner structures, but I must admit, there is some mighty fine technical work going on with some of the textures and the lighting.

"Well, Lionheart, that doesn't sound so bad, why the overall negative review, then?"

The writing and a large chunk of the voice acting.

The stewardship of the Halo universe continues to massively disappoint. The wrong people are making these calls at 343 and/or Microsoft, and that assessment allows for the possibility that Creative Assembly was the one who actually had full creative license over the game, which I strongly doubt.

The writing is just bad. Whoever wrote this has never served in any military, and WOW does it show. Particularly cringe-worthy is the dialogue of the marines in-game. Their idle dialogue and other lines are just... ugh. It was almost like someone held a contest to see who could lampoon military stereotypes in the most absurd way, and the 3rd place runner-up was chosen to write the dialogue for UNSC Marines in Halo Wars 2.
It feels like it's written at a pre-teen's level.
From Halo's best writing and universe-design to the writing and universe-design experienced here, it feels like going from this
http://i.imgur.com/81HkO3K.jpg
to this
http://i.imgur.com/jWsEQTU.jpg

And in some ways, it is even worse than that, though I don't want to go into that here.

Regarding the voice-acting work, Cutter sounds good. Anders is plenty fine. Isabel and Red team, though... geeeeeeeeeeez...
It's not that the voice actors were amateurs -- that's not what I'm talking about here, because they weren't: it's that what they were told to say, and how they were directed to say it, just makes me weep. It is *so* weak. Alice's voice in particular comes across as "try-hard tomboy" or "I built a shrine to Michelle Rodriguez in my attic" without interruption. Douglas sounds very unintelligent, though the entirety of Red Team sound like they would have to scratch their heads and have wrinkled-brow, confused expressions on their faces whenever anyone uses words greater than 4 syllables that aren't related to shooting things or blowing things up. It's entirely incongruous with the mythos surrounding SPARTAN-IIs.

Anywho. You'll see and hear for yourself when you watch the game's story on YouTube (here is one option: https://www.youtube.com/watch?v=g-W_m6cPbXA), which I strongly recommend over buying it. Regarding the bugs, the one that irritated me the most was when Warthogs would get stuck in the ground in one particular mission, and you wouldn't be able to do anything about it. You couldn't even destroy the vehicle with your own forces, so unless an enemy force came and took it out, it was just stuck there the rest of the match. And if the warthog that got stuck was one that you had placed a member of Red team into while it was working earlier, then that Spartan is just out of the match for good as well.
Well, that bug, AND having to restart the game because the loading screen got stuck in an infinite loop. ...and maybe the bizarre AI glitches in both campaign and skirmish mode.

Halo Wars 2 is just more of the same bad stewardship, folks.
That infuriating mixture of a couple of parts "Whoa... ... ...so cool!!!" and so many parts "inexcusable." Maybe one day, the people at 343 that genuinely love Halo will be in a position to reclaim Halo's potential. But we're not there yet.