What is super 100s fabric?

Ebay has a guide on this, and I am basically basing my answer on what I found there, as well as some other sources. Apparently, the number relates to the length of the yarn and how much it can stretch. The higher the number, the "finer" the material. However, this is not necessarily true, as the higher numbers also are more delicate, likely to wrinkle, and can only be spot cleaned.

At the end of the eBay piece, they advise to stick with super 100 or 150, and don't bother going up above 150 because such fabrics have the disadvantages listed above.

Or, you could go with a regular "worsted" fabric. The supers are lighter weight, but that is not always what you might want anyway. So, it would be wrong to say a super 150 is better than a super 130 or super 100, just as it would be wrong to say any of them are "better" than a worsted fabric. It depends what you want in terms of look, weight, durability, wrinkling behaviour, etc.