When I bought my first ser of the Brownell's Magna Tip bits their Super Set wasn't available. I mentioned having the Chapman Gunsmith Screwdriver sets years ago it was a good choice but it is limited especially with bits sizes.
I also had a set of the Bonanza / Forster screwdrivers.
I do have the Grace screwdrivers but these seem to be your basic wood handle screwdriver ground with a parallel tip.
When Brownell's came out with the Super Set rather then buy a whole new set, I made up a list of the bits I thought I'd use the most by using what I already had as a guide, and by looking at the gun we have. When I would place an order I'd buy some bits filling in any gaps as I went over my list. The versatility of the Magna-Tip bit sizes as well as some specialty bits is one of the best features of them.