The only slippie in my small collection that has half-stops is my red bone SS Case Peanut, I actually like them, it gives the knife a more precise, finished feel
as far as opening and closing a slippie goes, I tend to use the nail nick through the entire arc of the blade for opening, and as far as closing goes, I've never been bitten when closing a slippie, my old Boy Scout totin' chip training reflexes are heavily ingrained....
with the slippie open, I hold the handle scale in one hand, fingers holding just the edges of the handle, far clear of the closing path of the blade, with the edge facing down towards the ground, I place my other hand flat against the spine of the blade, both hands flat, I then carefully pivot my palms down and towards each other, allowing the knife to snap shut on it's own
in my 29 years of knife use, I have never been bitten by a closing slipjoint, that old Scout training works well....
I have, however, been bitten plenty of times by being slightly careless around locking knives, the Spyderco Dodo is extra nasty, especially because the ball lock allows you to drop the blade closed by simply pulling back the ball, there have been times when I left my pinky just barely inside the blade's closing arc, and the Dodo has a rather vicious bite....