I own both the G27 and the XDs. Both are snappy. Both are lightweight. The XDs has better sights unless the G27 is equipped with night sights. 11 rounds of .40 is better than 6 rounds of .45 IMO. I haven't weighed my G27 against my XDs, but my G23 loaded with 13+1 155gr Gold Dots weighs 4 oz. more than my XDs loaded with 5+1 230gr Gold Dots. I shoot my G27 as well or better than my XDs. In my personal experience with both, the G27 has a better trigger than the XDs. The mag release on the XDs is alot stiffer than the mag release on any Glock I own, and I have a few. The slide stop on the Glocks are better than the XDs as well. The XDs is thinner, by about an 1/8", but IMO, that's not enough to mean squat. I CC my Glocks in a CRST and have a CBMT on order for the XDs, which should be here in the next week or two. Once I have that, I'll be able to give a bit better comparison on concealed carry of both guns, based on the same holster.
Gen 3: G19,G20,G23,G26,G27,G29,G30,G30S,G32*,.50GI
Gen 2: G19
Gen 4: G17,G22
Gen 1: G17
NRA Life Member. www.1911addicts.com