The stock spring is the 19lbs. spring right? Apparently the XD9, XD40, and XD357 have the same recoil spring. I personally think 19 is a bit strong for a 9mm, but as long as you shoot with a firm wrist, it should pose no problem. However, for me to say that and not reprise would be hypocritical. I'm looking to use a lighter spring for a 9mm conversion of my XD40 and I've done some research on it. Don makes a good guide rod which uses Model 1911 springs and he's not too expensive. May even be less than Wolff? $20 for the guide rod I think and I found an 18lbs. 1911 recoil spring at a local gun shop for $7. There is another thing you can do, but I won't recommend it until I've fully tested and dubbed it safe and effective. The thread for that can be found here: (http://www.xdtalk.com/forums/hs2000-sa-xd-accessories/92222-poor-mans-guide-aftermarket-springs.html)What does this actually do for my XD9? Pros? Cons? Shopping around for enhancements for my gun but not sure what I want yet besides new sights. And for only $30 why not right??