You can't say a "Warmer" tint is better really, it's wrong. Skin tones with a green cast make people look ill. If the colour output is too far away from neutral some will be too strong and some too weak. Excusing a yellow/green tint as some kind of improvement is drinking the Apple Kool-aid a little, so to speak.
Apple should at least give us some calibration option since the only way to access that is by jailbreaking. This is how wrong my iPhone 5 measures and from what I've seen they're pretty much all like this:
The iPhone 4's cooler blue tint was much closer to correct than this, it's just pretty poor when the iPhone 5 is partly sold on the amazing colour depth and screen, if the colours are wrong and tinted then that doesn't really count for much. If you see a calibrated screen next to this you'll understand how much of a difference it makes, everything looks better.
The iPhone 5 screen is a bit of a disappointment as most of the people I know with one preferred the look of their iPhone 4, especially when compared side by side. I know a load of fanboys will chime in and say they preffer pissy yellow to over-clean blue but the fact is it measures farther from neutral - it's not as good.