Southard's rather curvy bellied blade shape is my biggest design concern. But rotate the wrist a bit, and I'm sure it produces more "flat" cutting area.

As for flippers, it's great when you need it. A lot easier to hit than a thumb stud--to get the blade started, if not fully deployed--depends on how encumbered you may be at the time of need.

If you, for example, carry tip-up RH and press the knife to the back of the pocket...the pocket helps to keep the blade closed and you can also slip your finger onto the flipper as you retrieve the knife from your pocket. Pretty fast and smooth deployment as soon as the knife leave the pocket.

As for keys...that's a bigger riddle. I try to never put them in the same pocket as my primary EDC knife. But that's not always possible, so it's an ongoing riddle.