Something that's been picking at my brains...

[JERRY2KONE]

The three images provided easily show why no one uses straight slot screws any longer. I would imagine that they will still be around for a long time to come, but I will not be using them on anything that I build simply because they are not worth the time put in to messing with them. Any one of these comparisons would work much better and have less chance of being damaged while driving them in or out of your work. The allen head is probably the most commonly used of the three, but I would think the other two would strip less and give you more use of torque holding power.