Wow. What a read.
I'm heavilly leaning towards this tune due to the background in EcoBoost engines, and the obvious understandings of the differences in this PCM from other engine managment systems.
This Stormcrow guy (or girl, I suppose) doesn't seem to understand the fact that this PCM uses completely different logic to determine fuel tables and required boost and spark timing. Just because you don't understand what's going on doesn't mean it's wrong. You're a self-admitted enthusiast, questioning professionals with a longer history of tuning this specific engine platform than you have tuning anything. A 600hp 350 is fuck all. It's a build you can do with a few clicks of a mouse on e-bay. It's laughable that you think that's an accomplishment to hang your hat on, or grounds to bash them into the ground with long-winded and uninformed rants. There's a reason they don't use the same software as everyone else, and why they get way better gains. And they operate a business. If they're the only one in the game that can do what they're able to do with the factory PCM, why on earth would they want to reveal anything about how they do it? It frustrates me when non-professionals question the word of pros without the depth of knowledge to do so. A little bit of knowledge is a dangerous thing.
This idea that a tune needs to be done for a specific area is also silly. They're not carburated engines. You say "well how can their tune that is written in Illinois work fine in Atlanta?" ...How can my car that was built and tuned by Ford work just fine in Vancouver, and the same car with the same factory tune work just fine in Florida? When you write the PCM programming to work as stock, with modified variables and calculation tables, guess what? You can make more power, while having it adapt and learn like a factory PCM. You don't have to retune a stock car just because you put a CBE on it, why should you need your tune re-written for it either? If your tune is so volitile that it only works properly in one approximate atmospheric condition, it's a pretty shitty tune. JDM ECU logic is practically archaic in comparison to an EcoBoost PCM, so it's not unreasonable that tuning houses who formerly specialized in JDM stuff aren't able to unlock as much with a PCM that they A) can't access or manipulate large portions of, and B) operates completely differently to what they're used to. Ford had to make this sellable, insurable, and safe enough that the 18 year old kid who convinced his mom it's "just a Fiesta" doesn't kill himself. Of course they left a lot on the table. That's the part that tuners take advantage of. Livernois just seems to have a much better grasp on how to do that than most of the other tuners. Doesn't make the other guys wrong, just makes Livernois better.
Also, fuel quality is of course important on a TDI engine, but DI engines get dirty because they don't spray fuel into the ports. The intake clogs and pollutes itself with blowby oil and the back side of the intake valves cake up. When we pull a head off an EcoBoost, the exhaust valves are usually cleaner than the intakes. A fuel system service won't fix that either. A catch-can and occasional vacuum induced intake cleaning with SeaFoam or something will. It's an issue common across all DI engines. Ford seems to be having better luck with it than a lot of others. Hyundai having some of the worst problems besides VW.