No question: I have a Mantis by Alan Folts. Awesome knife, great sheath--it's a well-thought-out system. Mine was the only one with green Micarta when I bought it (hey, for a Mantis, it seemed only natural) and also the only one with a groove for the index finger--but Mr. Folts told me once he made it, he thought the finger groove was a good idea. Having used it for a few years, I agree. The kydex isn't as tight as it once was, but the finger groove still helps me draw it.
It's small, sharp, extremely pointy, and fits the hand perfectly. It also weighs next to nothing. I still love it. It was my first custom, and I've had others since, but none to match it.