Caught a free advance screening of this yesterday.
It wasn't the greatest, but it wasn't terrible either. I'm sure some will disagree on that.

It was basically like one of those schlocky 90s B-movies, as Jeremy Jahns put it. A different director like Phillip Noyce (who I saw was previously attached to it, on the previous page) could've unquestionably turned this into a better movie with tighter plotting/writing and better cinematography. It did look a bit cheap at times, almost like a big-budget TV movie of sorts.
To its credit, I thought it was pretty entertaining, and although the suspense factor could've been better, it was still relatively suspenseful throughout in terms of the sub scenes and the other scenes above ground. The ending was just a bit cheesy at how the events turned out, but overall this was a moderately fun flick. A more capable director (like Noyce, Fincher, Liman, or Greengrass types) would've likely made a more "serious" and suspenseful film with more gravitas, but the direction this went wasn't bad either, it just made it feel like a schlocky 90s movie, not too far off in tone from something like Under Siege or Executive Decision. Compared to Butler's recent previous movies, I'd call this one closer to London Has Fallen than Olympus Has Fallen.
And I honestly didn't realize that was Gary Oldman the whole time until the end credits. The makeup jobs on his characters in recent years have been getting better!
Edit: I just looked at the previous page and noticed this thread was started 10 years ago?! Hot damn, that's a really long time for a movie like this to be in the works and finally get made!