The thing is...here in my house I have yellow/brown 4G signal and green 3G signal.
In a long deep sleep time (at nights) 4G consumes a bit more than 3G.
But during the day the difference is a little more significant.
I can get 4 hours of SoT with 3G. But 3 hours with LTE (or 3 hours and half).
I'm pretty sure that with a perfect LTE signal I would even have better battery life (like almost 5 hours of SoT).
But here is still experimental.