Its good, in that its got about every security screw that I've ever needed taking apart things manufacturers don't want you taking apart. Because its just rare security bits and not an "every day use" phillips, flathead or torx driver I can't speak to their long-lasting durability. Still, I've never stripped one had any issues. They feel pretty solid to me.
Let me put it this way. Would you use these if you were building computers all day, or a installing car stereos, or something like that, No. People buy the above 54 piece kit and use it in a professional environment and wonder why it doesn't stand up to abuse. Its not for that. But these are good kits to have around in cause you look in and opening and are scratching your head because you see a pentagonal screw with a small rod protruding from the center.
I've owned both sets for a few years, they see use a couple times a month. I have other standalone screwdrivers for everyday use.