Pros:
a). The processor is a beast. it handles anything very smoothly, without a single lag.
b). the screen is awesome. you would love to watch movies & pictures in this phone. the 4.95 inch screen full hd screen with 445 ppi is the best you can have.
c). adreno 330 gpu does amazing work in handling all the graphics
d). 2gb ram
e) kitkat gives a wonderful android experience
f) camera is good, may not be the best in low lighting otherwise good, specially after the update . The HDR+ feature works very nicely.
g) if you love gaming, then you will love the phone .
h) reading news & magazines feels great in this phone due to the large screen with high resolution.
i) it is very light . back panel gives a nice grip.
cons
a) the major con is the battery. it has a battery of 2300 mah, which is normally good. but this phone has a 5inch screen with full HD, so the sreen drains a lot of battery. nexus 4 had 2100 mah battery. Nexus 5 should have a maor jump in battery. LG G2 has a 3000 mah battery which has the same processor & a 5.2 inch screen. Something like that would have been better. But it still manages to give backup for nearly a day.
b) auto brightness of the phone works too well. it gives you more brightness than required, eventually draining your battery
c) the speaker sound is very clear but a bit low. could have been better.
d) auto rotation feature of screen sometimes doesn’t work that well, it is very rare though.