hughlle sucks for u, i use my s3 allday long love my battery life too. i sold my ultrabook no regrets.
I've used it all day long (as has a class mate his) and the battery life is indeed great, but the performance just wasn't there for me. You have to take into account that this was being used alongside an SP3, and now alongside an SP4, so the performance hit was always going to be very noticeable for me. MY classmate is more than happy with his, because it's the only performance he knows.