iOS 5.1 Battery Life

Has anyone had an improvement with their battery life after iOS 5.1? I don't have anything scientific, but my observations are:

• It was significantly worse on the first day; this is probably a combination of my playing with Siri in Japanese, and maybe something is "rebuilding."
• Afterwards, it appears to be the same. However, I did go on a trip, and travelled around town a lot, so maybe I put more drain on the battery than usual.