My gap and sand wedges have seen lots of use from practice and play, and I was planning on replacing them. Saw the Groove tool, and gave it a try. I had to clamp the clubhead into a smooth-faced machinist's vise to hold it securely, then clamped that vise into my large bench vice to hold it steady. I used the square point of the cutter to convert my v-grooves to box grooves. I pushed the tool along the groove on the first pass, then pulled it back on the return pass, and repeated until the bottom of the groove was flat. Forged clubs, so fairly easy to re-cut the grooves. Stainless clubs might be more difficult. Groove edges are sharp, put some good spin on the ball for those difficult short-side chips. I regrooved 3 wedges in about 20 minutes, once I had a way to secure the clubhead. Would be difficult to use effectively without a secure way of holding the club.
Pros: Quality, Durability, Easy to Use, Good Value