If you're choosing a belt for woodworking, choose an open-coat Aluminum Oxide. For finer depth control on veneers, chose a closed-coat Aluminim Oxide. Closed coat Zirconium is the most cost effective belt when sanding metal.
If you're comparison shopping from a competitor's website, you may be confused regarding SAIT's "Blue Line", "Economy Saver" and "Quick Ship" title in their products. These are all the same products, but the Blue Line is packaged for retail sales in a plastic clam-shell package. While the Economy Saver is rubber-banded together. The 'Quick Ship' means they're Sait's non-customized belts (meaning they're not custom made to the user's unique requirements). We've simply removed the terms in our listings to make things easier, but they're all the same belts.
There are lots of belt makers out there, but we deal only with Sait because they're tough, USA Made, and -by focusing on one manufacturer- we're able to pass our volume pricing to our customers.