I own a Walther PPX.
It's ergonomics. I'm a tall guy with large hands, and the grip fits wonderfully. It doesn't look great to most, sure, but it feels great when shooting.
Most overlook this gun due to the weird shape of the grip and it's chunky slide and high bore axis, but it's very accurate, it's a pleasure to shoot (very, very good trigger and good ergos), and it's very reliable. What more can you ask from a workhorse gun? Over 2000 rounds through mine w/o a single failure, not even a small hiccup.