I like mine alot. It's been my go to black and grey shader for about a month since I got it. I use standard tubes and needles though so I can't help you out with the carts. I got the 12v too. My ONLY complaint is that I wish it had a little more speed on the top end of its rangs as I find myself using it around or at its max voltage of 14.5. I wish it would go faster. It seems to hit plenty hard though. Pushed a 15 mag and an 11 round just fine. The weight and balance are awesome. Its super smooth and very coil like. I kinda wish I would have gone with the 9v but Im super happy and will be keeping it.