Great guide, very nice summation of what power-mining is, with plenty of helpful information. My only suggestion would be for you to add an hourly xp rate, as I'm sure many people would find that quite useful. I realize you have the xp per second, but that really isn't an easy, or realistic, number to work with, when compared to an hourly rate measurement. I also agree with the above poster who commented on the time spent mining. Power mining for 3 hrs straight is really hard on the eyes, back, fingers, etc, so i think taking a break every hour would be much more beneficial. Other than those small things, nice guide!