Here is a photo showing some of the things I was talking about.
The left awl is one of the Tandy all-in-one that I bought before I knew any better. Dull as a butter-knife from the packaging, and much too much taper for me. With that much taper in the blade, you have to control the depth carefully, and with thick leather, one side will have a hole considerably larger than the other. It is also fairly long so that it's a little harder to position the tip when your wrist moves around. It does, however have a relatively broad tip that makes it easier to find the correct angle when using pricking irons.
To the far right is, If I remember correctly, an Osborne awl. The blade is relatively long and very narrow at the tip. The length can make for larger movement at the tip with every movement of your wrist. The narrow tip till give no real help in finding the center of the slit, nor help with the angle of the awl when using a pricking iron. And yet, over all width of the blade is comparable to the small Seiwa to the left.
The middle three are Seiwa awls. They are relatively short blades to help with tip control. The blades are straight sided once past the tip, so the hole is consistent on both sides. The broad tip also helps to align with the marks made by a pricking iron.
One would think that the Osborne tip, being so pointy would penetrate more easily, but there turns out to be very little if any difference.
Bill