I had it on my last laptop and lost it when it crashed. It is fascinating software and it was fun to tinker around with. I used it to differentiate powder performance with different barrel lengths, for instance, and to speculate regarding different rounds. I would never use it to replace traditional reloading manuals, however. Algorithms are not experience, and formulas are not real life. I will buy it again, am glad I bought it the first time, but consider it a secondary source to traditional manuals. If I were a wildcatter, it would be invaluable, but if I can find a load on paper, I am much more comfortable.