I have several sets, including the glass panel and Shaker door set. They are great, seem very well made and the matched feature is really nice. I have the easy set jig for setting his brand of bits. What makes this so nice to use is that it adjusts to the thickness of the workpiece, so setup is very precise and easy. You may find yourself not bothering with test pieces after awhile. I fear I sometimes sound like a shill for the company, but Sommerfeld has earned my respect by producing good (if a little pricey) products. There are many brands of bits and jigs out there, but I think Sommerfeld's are hard to beat. His videos have been among the most helpful I've seen and I have the full set. Lots of good technique and he stays with the process all the way through so you don't miss a thing, or a trick.
The more I do, the less I accomplish.