How much better is the Nexus 5 camera over the Nexus 4?

I currently have a Nexus 4 which seems to sub potatoes and feces all over a photo regardless of conditions.

I remember that the Nexus 5 had a disappointing camera but in an Android update got a significant boost on the software side.

How much better is the updated Nexus 5 camera compared to the 4? Maybe I just got a bad sensor or lens but mine is pretty awful. The lens just seems incredibly slow so that even a picture of a pet in good light ends up looking like some sort of Cthulu mythos shadow demon because my dog moved her head slowly half a cm.

I have an RX100 II so I don't need a full PnS replacement but a camera that improves upon the OG Razr would be nice so that I don't feel like I have to take a camera everywhere.