This is a great kit.  I contemplated buying the complete kit as opposed to the smaller ones with less hole saws, but I'm glad I have all the sizes.  I'm using these in the construction field, more specifically as an electrical contractor.  I haven't used even half of the sizes YET, but I have used them on drywall, wood and metal.  I needed a very specific size hole cut out for an electrical panel enclosure and didn't have a hydraulic hole punch kit.  So I pulled this kit out, found the size and it cut the hole very well without dulling the teeth.  Having all the sizes may save you money and time from having to go out and spend more buying them individually and waste time driving to get one when your on a job and just need one particular size to finish something simple.