I have three of the Onion/Kershaws, an old style Task, an old style mini-Task, and a Whirlwind. I've never even come close to cutting myself on them. Although I normally carry a small Spydie during the week, which requires the circular opening motion, the straight push for the speed-safe is perfectly natural for me. I've been very pleased with each of these models. I roughenned up the end of my thumb from the serrations on the thumb stud when I first got the Task (played with it a lot), but that wouldn't happen under normal useage.
If I had one suggestion, it would be to put thumb studs on both sides of the blade. That way you don't have to be so particular about which pocket you drop it in.