Several months ago, I purchased the Kreg K4MS so that I could build the Lego Table as outlined on the companion "buildsomething" web site which exclusively uses pocket hole construction. I have considerable experience with conventional construction but I thought I would give it a try because of the reviews that claim it is quicker and sturdier than conventional joinery. I would disagree for a couple of reasons.
First: I don't feel as if it is quicker at all because it takes considerable time to lay out and mark and drill all the pocket holes required. I believe I could have made it with dado and rabbet joinery much quicker.
Second: Many of the pocket hole joints were very weak because although I purchased a quality grade of ¾" oak plywood, a good percentage of those pocket screws hit voids in the plywood and they would not anchor tightly at all.
Third: Although I used genuine Kreg screws with a quality Bosch driver with a clutch set on a low setting, several of the screws protruded through the face piece so that the tip on the screw was showing. I had to put some washers on the screws to keep them from penetrating so far. Yes, I did adjust the drill collar exactly as instructed.
Given my experience with the pocket hole joinery, I must say I am deeply disappointed and I believe I will sell my K4MS and go back to conventional joinery.