-Bottom line up front---cheap to shoot. Who doesn't like that?
-Accurate. The fixed barrel design lends itself to good accuracy.
-Ergonomics. It's a 90% scaled down P226 and many new shooters I've lent it out to like the smaller grip circumference.
-Many different finishes available
-3 dot adjustable sights
-MIL/LE pricing is available
-With the exception of the slide mounted safety the controls mimic it's bigger brothers in the Sig line up making weapons manipulation drills applicable to the guns many would use in a real world environment.
-More complex to break down and maintain than some competitors (not bad by any means but I can see how some new shooters would be intimidated by it).
-10 round magazines standard
-Like many 22LR pistols, it seems to be somewhat picky about ammo.
Here's a video with some day & night shooting, disassembly/assembly of the pistol, and discussion of the pros/cons of the pistol.