Many of these same arguments were already made in the Ford Performance tune thread.
There are two arguments- equally valid.
One is that if you're going to tune, you should get the very best.
The second is that one doesn't need the "very best" when price, warranty, existing equipment and expectations come into play.
What is not valid is the "tribal" element that sometimes shows up in the discussion. I don't have a dog in the fight, as anyone who has read my posts has seen that I can be more than a little dismissive of vendors' claims.
That being said, if you want to argue "the best", let me tell you my opinion from an engineering perspective. I know of only one tuner who has tuned the most modified STs on the planet. This person is also the only person I'm aware of that has done something I thought nearly impossible- to use the stock ECU to control two completely different turbos with external wastegates in effect converting from the internal vacuum wastegates to twin external pressure operated wastegates while dealing with not only all of those challenges, but those of dealing with the ramifications of solenoids, etc without resorting to external wastegate control systems.
And for that reason- and not because I have any sort of vendor or personal relationship, my vote would be for ZFG.
