I went with the Command Center 2 to avoid the same things others have concerns about. There are lots of opinions around, and even some of the suppliers are selling the newer Command Center 2 matched to other brands of efi. First - it works fine. My 1973 had a factory vapor return line, I and I hooked it up with the assumption that the fuel return would pass through the vapor separator that feeds the four lines going into the tank. When I first started running the setup, it stalled, put me on the roadside. The CC2 got very hot and shut itself off. Roadside diagnosis, I found the return line was pressurizing. It cooled after a bit and ran and got me home. I took the return line and bypassed the vapor separator by the tank, to dump return to one of the tank feeds. Dead-headed the other tank lines. Also drilled a 1/8 hole in the bottom side of the tank cap to vent the tank for sure. Problem solved. The CC2 runs cool, using excess fuel to cool the enclosed pump. With everything else heat soaked under the hood at 160-190, the CC2 body shows 115-120. Feeding fine. I don't like the bulk, but I do like the consolidated system which is slaved to the ECU with variable pump rate control.