I was also a bit disappointed with them at first, vibrates like a bitch with disposables and I was wondering if all that about the Halo was just hype. Something changed when I started using heavy grips. I had also that splitting experience, now using soft nipples, just a small bend at the top of the needle, and very important to me bending the needle close to the soldering too.
It changed for better a lot, but still not using them when I need precision, I realized that start covering a defined area, like start shading from a line, it's difficult to see or not where are you starting from. At least not like other machines I have, where you can see and tattoo very precisely where are you going. Not my favorite, but it works very nice for a nice black and gray or blending colors in my opinion