They just lowered the cost of the X-36 to match the X-45 to get rid of old inventory. I think over the long term, the lower cost of the X-45 may prove to have come from some sort of reduction in quality... but maybe they found cheaper production methods with equal or superior quality. Based on what I have read, some think the X-36 feels better than the slightly modified X-45. I would like to try the X-45 to compare, but I will stick with my X-36 USB until it dies. At over a year, I don't have a problem yet. It is by far the best stick I have ever used.