A UK reddit poster got a hands on, based on what he saw the XL SOT is...

Depending on the use, that sounds pretty pedestrian to me.

True, it does depend on the use. With my usage patterns on my 6P, I actually get about 4 hours SOT. This is if I'm not using the phone with the screen on constantly--if I did that, it would probably be closer to 5.5-6 hrs. I suspect having Android Wear installed might impact my standby time, since that might be waking the phone more frequently.