SPOILERS DISCUSSED BELOW
I was gonna write a review of this but there are a ton of them already so I'll just comment here. You are much more kind to this film than I would be. I found the plot boring and it starts out just stupid... no military convoy travels with the precious cargo in the front, also when they run away after the capsule pops open instead of getting into their armored vehicles with 50 cal machine guns I just got irritated. It's kind of like how people would take the most stupid path to run away from Jason in the Friday the 13th films.
Later, way too much time was spent on senseless character development and recruiting, hence the 2 hour + runtime. From a "my living room with neighbors" perspective the whisper sequences followed by speaker destroying zombie screams is something that always irritates me, i had to watch this thing with remote always in hand. There is also continuity issues such as the "alphas" being much more difficult to kill but other than the "king and queen" they seem to be cannon fodder just like the rest of them.
The helicopter pilot not being at the meetup point only to have it emerge seconds from disaster is a direct ripoff of Aliens and probably many other films as well.
The gore was fun at times, I guess I appreciated that to some degree. Mostly, just like you I wasn't expecting much, and that is exactly what I got in the end. It was nice to see Dave Bautista getting work though, that's one upside. I have liked him since his WWE days.
I agree it was nothing exceptional but from a fun perspective, I was entertained.