I simply love this app.
It's very unobtrusive, allows one to eject a drive without having to open finder, and cleans drives of files that are seen as "junk" by windows.
Unfortunately, after a couple of months (and only by accident, when solving a problem using gfxCardStatus), I found out that this alone is responsible for a decrease in 20%+ of my Macbook Pro runtime.
Because once you click on it, it switches the discrete graphics card on, and never again switches it off. From then on, every app uses the discrete graphics card, consuming a LOT more power than needed.
If you use it in a desktop computer (iMac, Mac mini, Mac Pro), consider this review a FIVE STAR review. Otherwise, consider it a TWO star review.
I can't imagine why would you use the discrete graphics card for such a simple app, much less when only the icon is on the menu bar.
I'm currently not using it.