i can honestly say that it works much better with a pressure box added and the six gun adds tons of rail pressure. the combo seems nice but i think that the electronics might be messed up because i forgot to unhook the box on programming one time. As for the claims with a my six gun off and just injectors i had a dyno of 416 and with just the programmer i had 480 at the wheels. I couldn't believe it was so small considering the massive amounts of smoke it puts out. I then ran it with the six gun on level 3 and my previous run was 427 or something and i got 592 so as you can see that was a huge increase the torque went up a little bit i think it was like 1098 and then with the xcell it was 1143 but this thing dumps a lot of smoke now it's ridiculous. Always worried about being pulled over. I heard a ru mor that pulse width and duration type boxes tend to not get that much benefit from extrude honed injectors which is what i have from ats. I heard that edm's tend to be the better option with that type of box like tst or the pacific programmer. If i didn't have dyno numbers and i just had a choice between the program and the six gun, i would take the program in a second. It seems way harder and more responsive almost like a gas motor. I did have some electronic issues as well when these results were in the works. I'm going for reflash and new crankshaft position sensor and then dyno again. Let me know if you want i'll email u a video of the runs i do have with the six gun before the programmer and with the six gun after the programmer so you can see the difference.