I used to use custom made picks a few years back because nobody made large, tapered production picks. Now with these, I don't have to spend nearly as much, and they work just as well, if not better. The taper, or the angled part of the edge of the pick, offers a very precise and fast attack, while the thickness enables you to put more force on the strings, resulting in a, to me, more aggressive sound, all the while without you needing to hit as hard as you would with a lighter pick.
I use these picks on 7 string baritones mainly, playing fast and heavy, which is what they seem to be made for! The material of the pick is textured, and the inner area has little knobs for extra grip; certainly you won't drop these easily!
The best picks I've used in my 15 years of playing. Before going with custom picks I used mainly gator-grip 1.14 and 1.50, and these are miles ahead of them.