@Ricardus I completely agree, although I tend to think of triangle as a pain in the butt because of the scarcity of bits. Pozi-Driv can be driven by either a Phillips bit _or_ a square drive bit, but it drives flawlessly with high torque with an actual pozi-driv bit.
@Ricardus agreed, although I think the important geometry is the engagement surfaces more so than the overall external profile.
@elb Any bit that's conical in shape requires actual force to hold the bit into the fastener. Things like torx and Allen don't require that pressure for engagement.
@Ricardus That's true if the drive surfaces are an incline (like Philips) but not true if they are parallel (like pozi-driv or ... whatever that Japanese bit is that looks just like Philips but isn't). They're both conical in external profile, but the engagement surfaces meet at nearly a 90 degree angle, so they sit tight in their sockets.
Philips was literally _designed_ to torque out, and for some reason we use it for fasteners with moderate (though thankfully not usually high) torque loads.
@Ricardus See also hollow-ground flat blade screw drivers with parallel surfaces at the tip, versus your typical hardware-store flat blade with bevels.
@Ricardus That's what I'd call them, but I wasn't sure how widely-used that term is. In general, firearm screws have very high-quality cut heads with parallel sides, and hollow-ground fitted screwdrivers can turn them out with little to no chance of slippage.
Slotted is the absolute worst
Allen is terribly easily to strip if you're bit is slightly not right
Phillips is good
Torx is supreme
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko