I have been testing this phone for the past week or so and found it to be a big improvement comparing with the Optimus One I had before. Much faster and more importantly, unbelievable battery life.
I use my phone mainly as a messaging device(so my phone vibrate when I have email/im etc.). Today, I started out at 16% and it finally exhausted after 15 hours. So for my purpose, it can last for 100 hours or so(mostly wifi except 3G when on the road).
Also tried turning on the wifi-hotspot yesterday and it drained 25% in 5 hours. Which means I can use it when I am on the road and get a iPod Touch to mimic iPhone4.
Very satisifed with this device, it is quite light weight too, ~105g.