Nexus 5 VS. Galaxy S4-9295?

I don't have much time so I'll be dry and quick.
Nexus 5 all the way. It has and always will have the latest android (now it has the 4.4.2 update), better screen(IPS instead of AMOLED),
the camera is worse I'd say, newer processor(Even though both are quadcores), it has a TV-Out(on a click I share the screen to the tv via wireless), and also one pro-con(the battery is attached so you can't remove, but at the same time it extends a lot the battery life.. I've seen peeps reaching 1D6h using the phone).
Also for developers, you can enjoy the new Runtime (ART).
However, it won't really be a big difference for a developer to have either of these phones, you can always use a VM with android kitkat whatsoever, or even root the other phone to a ROM that has it.

I'd go for the Nexus 5 too, it gives a lot more for the money you'd spend on it...

I'm assuming you will want to root your phone, in which case, avoid Samsung unless you don't care about stuff like warranty. Samsung is closing up their phones and voiding warranty if you root. Without rooting, it's filled with junk and becomes slow quickly. Their new models are sometimes defective for which they will over charge if you don't have a warranty. I have a galaxy S4 and had to get the main board + battery changed within a month of buying because of overheating.

I would say to go Nexus for pure google experience without the bloatware other manufacturers put.

Xiaomi MI3!!