HI I am looking at the springfield xd in either the sub compact with 3 inch burrel or the service 4 inch. this is for ccw and the sub is 6.25 inches long and the service is 7.3 inches long. probably should go with the sub compact. I have been looking at xd and M&p by smith for a long time but I really like the extra safties on the xd I am new to pistols so I guess I want the extra safties because I am new to pistols. I was going to get the 40 s&w because I have heard so much about this caliber, but I have been researching and I have found that if you use a good sd ammo the numbers are almost the same for 40 and 9mm and I know the 9mm is much milder to shoot especially in a small gun. I seen in an article where federal hydrashok in 9mm+p+ has the exact same numbers for stopping power as the 40s&w and almost very very close to 45acp.and in pederal pda and remington golden saber the numbers are better in 9mm than 40s&w. Being that shot placement is the most important factor and the fact that if I use on of these ammos i stated I will not be giving up much in power and for practice the 9mm is much cheaper to practice with and my shot placement will be much better because of less felt recoil. If I am wrong please let me know.