Is it just me or is the iPhone 5's battery... TERRIBLE?

Look, I understand that it's got a whole new chipset, bigger screen and supports LTE and all that, but I'm rather concerned about it as my daily driver. I've come from an iPhone 4 (which I owned since launch) and, with almost identical settings, I'm getting 6hrs max out of a single charge.

(and yes, I know you can turn the brightness down (which it is) and turn off various settings - but seriously!)

Just as an example - watch Youtube on the train for 20-odd minutes - down to 70%!

Surely I'm not the only one experiencing this? I'd like fellow iPhone 5 users to shed some light on this!