I have had the G26, Shield and now the XDs 9.
I really liked the G26, liked the 10 round mag, that, with the pinky extension could be 12 rounds. It shot nearly as accurately as a G19 and could use G19 mags.
But, felt it was just a bit too bulky for summer clothing here where it is hot.
Switched to the Shield. Nice gun, very good ergonomics, shot very well. Nice and slim for CC. But...could never get the last round in either of the mags. So...that left me with 6 rounds in the flush mag, 7 in the extended (it could have just been me).
SO....traded for an XDs 9. I get the same slim profile, same light weight, same very good to shoot, accurate gun, that I can get the full 7 rounds in the flush mag and the full ....9...in the extended mag. 9+1 for 10 onboard.
Comes with two flush mags, but SA is running a deal (ends tomorrow?) whereby, if you buy a new gun, they will send you three more mags, two flush and one extended.
Of course, the XDs and G26 are about $100-150 more than then Shield.
To shoot, the G26 definitely. If you want an XDs that is more "shootable" try the XDs 4.0. Almost like having two guns, with the extended mag (comes with a flush mag and extended mag).
For CC, the XDs.
Hope this helps