imported post
All three of the weapons you mentioned are good firearms and I have shot all three of them. I don't particularly like the way Glocks feel in my hand and therefore do not prefer them. For disclosure on where I am coming from with my preferences, I 99% of the time carry either an Springfield Arms XD compact .45 or a Sig Sauer P228 (9mm). They conceal differntly and depending on what I am wearing, sometimes the Sig conceals better and more comfortably with the holsters I currently have. When I OC I carry the XD .45. My best friend is a Glock fan boy so I have been through the relative merits discussion numerous times.
Even if I liked the feel of Glocks generally, I personally would not purchase one in .40 as it is a high pressure cartridge and Glock .40s do not have a fully supported chamber whereas the Springfield Arms XD series does. I personally have never heard of a Kaboom! in an XD .40 (although it has probably happened) whereas there are numerous cases of such with Glock .40s on the internet. On the other hand, there are a lot more Glock .40s out there (many LEO depts use them) so the rates of failure may be identical.
My personal opinion (with which Glock devotees would disagree) is that the Springfield XD series is the next evolution of what Glock started. The XDs adds some safety features, has fully supported chambers in all calibers, and the barrel feed ramp is supported by the locking block instead of by the magazine lip. All that being said, excepting the backstrap safety, the Glock 9mm has all the other features to the best of my knowledge.
In the final analysis, it comes down to personal preference. The Glocks and XDs are not dissimilar. Glocks have significant advantage in parts availability for example. I find that most people have a fairly strong preference for the feel of the one vs the other, and that is what really matters. If you have good ammo in either brand, the one that is most comfortable for you to shoot is going to be the most effective weapon for you if you ever need it. As to caliber, I am partial to larger calibers for various ballistic reasons, however, if you are more comfortable and more accurate with the smaller caliber, it is better to put 2 9mm shots on target than an infinite number of .40 or .45 rounds into the wall behind the baddy. My 2 cents.