-The knowledge of the techs at ACI: We'll see if the following is true once I get my tank back from them...IF I ever get the tank back. The tech at ACI told me that my lack of consistency and accuracy using the low-pressure (blue) reg on my gz intimidator was the fact that the gz timmy needs 500-600 psi for input. He said he personally spoke with Bob Long who told him this.
-Quality Control is lacking: Out of the box, the pin on the regulator leaked. The hissing disappeared after two days of playing, however the tank couldn't keep pressurized for more than a week.
-Dependability is lacking: On my third weekend of playing with the tank, the burst disk went. I switched to my high-pressure PMI tank and the dismal performance of the gz intimidator switched to becoming fantastic. I attributed the poor performance of the gz intimidator to the gun itself. I never thought to look at the ACI bulldog tank. Consistency and accuracy went way up.
-Customer support is horrible: I finally gave up in disgust and sent the tank in. I didn't hear anything for a week so I called up tech support. They said that the regulator was definitely bad. They also said they would replace it for $45 and send it back to me. I said that was fine. After a week of waiting for the tank to show up, I called again, and they said that it was shipped a week ago. I asked for a tracking number, but they said that they would call me back. I called three times on three consecutive days for a tracking number, but each time they said they would call me back with it. Finally, today another week later, I called and they said that it hadn't shipped yet because they were waiting for my credit card number. They charged me for the $45 plus $8 to get it back to me in a week.
Get something else. The airsmith at my local paintball store said that ACI has been sued in the past because of its regulator design and performance. It's easy to see why.