This has been an issue since it came out, under all 3 version of OS10, and on 3 machines I was able to test it on. The things would get hot on the bottom, and battery would go down quickly. There was no apparent reason for it, would happen at random times when Change Reaction was running. Finally getting curious, I ran activity monitor on the side to see what I could sniff out. What I found is that changereaction.app would use a high percentage of one core, usually to the tune of about 40% or so. This was consistent on all OS10 versions; 10.6 through 10.8, and on 3 mac book pros. Anyone else seeing this?