I’ve used the Kreg pocket hole jig to repair a broken chair, build shelving, and customize framing around a media box. I like it because it’s simple to use, requires no glue and little woodworking experience, yet it results in a tight professional joint.
I also bought the right-angle clamp (basically a Vise grip with a pocket hole clamp end, model KHC-RAC), and it works very well. It helps keep boards straight and steady when making a 90-degree joint, and therefore made this unit superior to a more-portable plastic jig I had previously used. The best thing about the Kreg jig is it’s simple, doesn’t require a lot of space, and all you need is a drill to make it work.