Re: Springfield xdm or Glock ?
Either of those two pistols are fine for home protection; however, if you are new to semi-auto pistols, training and practice is very important. 40 S&W is more expensive to shoot, and for some people, the recoil can be an issue. My suggestion would be to buy a good 9mm, and become proficient with that weapon. 9mm ammo is adequate for home protection. 9mm can also be obtained in +P loadings with H-P bullets if a more powerful load is desired, after you learn the fundamentals and are able to achieve proper accuracy with FMJ range ammo.
R.I.P. WCO Dave Grove ... You will never be forgotten.