I have not used them, yet. However, I had a quite lengthy discussion with Dennis about them. He explained to me the process of developing the tips, the time it took, how many designs he went through to get to this point, the quality and the cut of the leather, and the testing involved. Dennis & I have known one another for a long time and have always been quite open with sharing experience & knowledge. It's something we have in common. I can assure you these tips are legit, and only the tip of the iceberg. The man is meticulous and picky. These tips wouldn't be on market if they weren't the best.
I won't bore you with the discussion details but his purpose was based on the fact that we, as cue makers, don't have a real good tip. It hasn't existed in quite a while, partly because it's very expensive & there's a fair loss ratio in testing. He wanted a tip that felt, sounded, and reacted like the sweet spot every time, regardless of placement. And he feels he has achieved it. I believe him. I'll be seeing him at the expo next month to discuss in person acquiring a regular supply to most likely become my standard tip on my cues.