The P320 comes standard with two high-capacity magazines. Most officers generally carry three mags, one in the gun and two on the belt. Having to purchase an extra magazine separately is a bit annoying and adds to the overall cost of using this gun as a service weapon.
In addition to the magazines, SIG includes a nice Kydex single-retention holster for off-duty wear. While it may not seem like much, the ability to carry a gun right out of the box without having to wait while you hunt for a holster is nice. I actually carried the P320 and made several draws from this holster, and its single, pressure retention design worked very well. The Kydex, although not overly thick or rigid, held up to some vigorous draws and showed little wear.
One excellent aspect of the P320 is the sights. It comes standard with SIG's proprietary SIGLite night sights.
Another big selling point for the P320 is the ability to disassemble the gun without pulling the trigger. This is accomplished via a single rotating lever on the left side of the frame. Simply lock the slide to the rear, rotate the lever, and the top half of the gun effortlessly slides forward and off the frame.
Personally, I've never been concerned with pulling the trigger to get my gun apart. After all, if we're following the firearms safety rules as we should, there should be no unintentional discharges upon doing so. That said, I do understand the reality that a large portion of gun-carrying law enforcement officers are not what one might call "shooters" and may be known to skip a step or two from time to time. If we can keep these folks from pulling the trigger when they take their guns apart that's probably a good thing.