I have shot both and liked both a lot. I also shot the Hoyt and bowtech and liked them a lot to. But I bought a Halon 6, I don't know why it was the only bow I didn't want to put down. Like everyone else said to me try them all and pick your bow. Its not a brand strong power bunch here, there all good in my opinion.
Have not shot the Z3 but it will be hard to beat the NoCam. That is indeed one of the most accurate bows I have ever shot. Mathews makes a solid bow either way. I would recommend shooting them both and see which one you like and fits into your budget. Also be on the look out for people selling the HTR in favor of the Halon or HTX. Good luck and let us know which route you go. Sorry I couldn't provide more feedback.