1. I havent noticed any more battery loss by using this app.
2. I suggest you use setcpu and also set up some profiles. This will help save your battery.
Since your using the app, I suggest you read through the op of that link and familiarize yourself with the app. If you have any questions about it, post your questions there. In that thread are some very talented and helpful people that have been working on this a lot long than I have.