I just saw this a few days ago and was surprised by how good it turned out to be. Of course those deserted shots of London were fantastic. And after so many minutes of isolation, when Cillian goes into the church and says hello, that sudden jerk of the bodies turning to stare at him was very freaky. That worked so well.
The movie picked up a lot too when we meet Frank and his daughter Hannah. It was so surreal to see how kind he was to them in all of this madness, and how protective he was of his daughter. That moment when he is infected with the virus, and he tells his daughter in the last few seconds before he turns that he loves her was very touching.
I'm still 50/50 when it comes to when they stayed at the military compound. It plausibly works, but it was so different than what I had expected the climax to be. I'm still leary about it. And of course the ending gave a satisfied feeling as it left off that they were going to be rescued.
But on a side note, I saw the alternate endings and how I wish the one where Cillian dies at the hospital would've been used instead. It just would've been more fitting, almost poetic, to have him start out at a hospital, then at the end die in one again. And it was also more touching to see the girls try and save him, then finally say goodbye to him, especially when Hannah pauses to acknowledge him before picking up his gun and leaving with the other woman.
Anyways, still a great movie.