I bought a Hawk pen a few months back. Grant it, it is an awesome machine and runs carts very smoothly and quietly, but for what it is it is severely over-priced. The other part I couldn't get over with these kind of machines is that you can't take them apart (well you can but it's a process) to clean up inside the machine in the event of an ink flow back. I was very meticulous in examining the push bars on the carts at the end of a tattoo session to make sure there wasn't any flow back or ink spatter that made it's way up and the first couple pieces I did I had no issues and would swab out the inner housing with wavicide and alcohol for good measure and autoclaved the grip. After one session though, I noticed a black smudge on the cart drive bar after the session so I stopped using the machine and decided to tear it apart to see what this smudge was. As it turns out it was the grease that was around the drive mechanism that made it's way down and was staining the drive bars of the needle cartridges. That turned me off from these style machines altogether, just the "what if" factor isn't really worth it to me. I just got an AXYS rotary in yesterday and got to use it on a piece and that thing is every smoother and quieter than the Hawk pen and over half the price!! Very pleased with the AXYS so far.