I find Camera to be better on
Moto X than Nexus 5, specially quick capture as it has proven helpful. The camera has improved alot since 4.2, plus it's wider than Nexus 5, just keep manual exposure control and focus and HDR on and photos will turn out to be great.
Here are some samples i gathered from camera album of my own X,
https://imgur.com/C5iEZGW
https://imgur.com/R2ZKe0T
https://imgur.com/2RnDfbz
https://imgur.com/41mr0hY
Performance wise, on paper, it's definitely not better than Nexus 5 but that would be hardly seen IRL, Still.. it's a huge deciding factor so Moto X loses here.
Altough it has travelled a long way from 4.2.2 to 4.4.3, the future updates were guaranteed to be there before
google sold it to
lenovo, and until lenovo keeps it as a separate company, you can expect updates on this phone.
Also it's wise to wait for upcoming phones, you can expect moto x+1 this august.
EDIT: for photosphere, fisheye, background blur-type photos, you can use Google Camera from play store for that..