The XDs carries completely different from the other XD pistols. My very first off duty piece was an xd subcompact in 40 and I agree, it is way too bulky. The XDs and the shield both have very similar dimensions with the short mags in. The XDs short mag is 5 rounds and the long mag is 7 rounds. The XDs extended mags add significant dimension and makes it blockier and harder to conceal. I guess you can carry 5+1 and a 7 round mag for 13 rounds of 45. Alternatively you can carry 7+1 in a shield and a 8 round mag for 16 rounds of 9mm. I have both in crossbreed supertucks and they both carry just as easily. The XDs has a nice aggressive grip also. If you're an XD guy you will love carrying the XDs, but you have a chance at a shield get it also. Bottom line is that both guns are excellent off duty pieces. You won't be disappointed.