Just traded a Glock 34 MOS with Burris Fastfire plus $100 for a new Sig P320 X Five. I didn't like the Glock as much as I had hoped, although it never failed. Sig felt so good in the hand, the trigger felt better and I really, really like the flat trigger. It feels very similar to the on my AR.
From all I have read, the X Five flat trigger weighs less than the regular 320 triggers and is much less of a risk to move when dropped. We shall see.
At some point I will find a way to mount a Vortex Razor reflex on the Sig. Hope someone makes a mounting plate sooner than later.