I chose a Springfield XD40 sc as a carry gun several years ago. I replaced the factory sights, as my only mod, with Trijicon HD night sights. After carrying for a while, I purchased a second one, fitted it with the same sights, and, after reliability testing, keep it in the safe as a back-up to my carry gun. If my no. 1 carry gun fails, I replace it with the no. 2 in the safe and send the no. 1 back to SAI for repair.
I believe that one should stay with the gun you train with and carry so thinking about a different carry gun is unnecessary. In my military experience, when in crisis, you revert to your training on a particular platform, regardless of weapons system, and, accordingly, I want to revert to an identical platform. I thank G-d that I have never touched my carry gun outside the practice range and pray that I never do. As to this, YMMV, but I hope it never does.
God luck,