Average. I was a bit underwhelmed, actually. The story wasn't the great. Really, the grabbed the TARDIS at the exact moment he lowered the shields? Convenient. Really, he needs the help of salvagers to find Clara in his own ship? Weird. The solution was a bit out there, and literally used a reset button!
I also was not impressed with the interior of the TARDIS. In some ways, I actually preferred Tom Baker's romp through the TARDIS in The Invasion of Time. We mostly got corridors and echoes of the control room. We got extremely brief glimpses of the library and pool and a couple of minor rooms. I actually prefer the cozier feel of the TARDIS in the classic series. The new hallways are just kind of bleh. Just sort of there.