I've just given my older Kreg jig to my son and was after another one and was originally looking at the Kreg K5 but watched a few videos on the Armor tool version including this one https://www.youtube.com/watch?v=Feb3LZq_zTg and became very interested. Unlike the Kreg it has infinitely variable block height based on timber thickness as well as self adjusting collar position.
Any owners out there with a comment on performance, reliability and longevity