in that real life usage case i get sometimes 8 hrs and sometimes more than 15. i dont cut low on the most important things as internet and phone, sms and im (3g).
i wait with wifi till the drain-bug is fixed and this way i am satisfied its not great but satisfied. when im at home i charge it whether its half full or empty and when im out i sometimes have to think about my use in order to maintain being reachable. but thats usually due to lack of charging. getting a 2nd battery i will never. if i notice i cant cut it with the one battery i think im gonna get an other phone. that'd be ridiculous. its balancing on the edge but im sure it has to improve one way or the other in the future by software etc.