They're all good. Bottom line first... Which caliber do YOU want?
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together. You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek
No experience with the XDs or the Glock 30, but I thought the Shield was great. Would consider it for a carry gun in a heartbeat. Good shooter and surprisingly accurate for such a small gun. The Glock 30 seems like an odd choice in there. Why not the 26 since your other choices are 9mm?
"For every problem there is always a solution that is simple, obvious, and wrong." - Mark Twain
The reason for the Glock 30 is I already have a Glock 21 which I carry. It uses the same mags and everything and has the exact same controls so break in period for me would be zilch. Plus I get a huge discount on Glocks.
I am considering the 9mm because I know the wife would like to start carrying as well. I am leaning more and more towards the M&P based on price point and standard features I can get with it.
Well we discussed it. She loves Glock but due to children and her own awareness of how much she is going to be distracted she wants something with an external safety. Which I completely agree with even though my primary carry is a Glock.