While this back-up gun is not the same as my duty weapon it has worked out pretty well so far. Many people belive if you carry a Glock 22 then you should carry a mini Glock in the same caliber. There is nothing wrong with school of thought, but if you are looking for something different the Springfield XD9 is an excellent firearm.
Some features include:
Striker status indicator
Loaded chamber indicator
Accessory rail
Calibers 9mm, 40cal, 45acp

It is worth checking out.