RTFA yourself. People are complaining they didn't get the "10 hours" of battery life Apple Promised them. Apple didn't promise them 10 hours doing whatever they want. .. nor did they promise "10 hours of doing the same thing your old machine did". They promised 10 hours of battery life under the conditions of use they advertised which did not include using Chrome which sucks... or driving a external displaying.... while on Battery (seriously why would anybody even need to do that anyway?
The one example of long battery life was someone who had 92% left and is referencing the estimated life. I'm sure we've all seen the rosy estimates on our devices only to have the battery life decline in a non-linear fashion.