2019 GT supercharger...roush or whipple?

I'm not too knowledgeable about the S550, but I'm pretty sure that Ford Performance offers a 700 horsepower blower for em, and when installed by a Ford Performance certified mechanic, will retain the car's warranty. I'd check that out. Just my 2 cents.

Going off of what I know for previous generations, you can't go wrong with either choice... dur. The difference is that the Roush is an Eaton R2650 (Twin Vortices) blower (https://www.eaton.com/us/en-us/catalog/engine-solutions/tvs-r2650.html) and that the Whipple is a Twin-Screw. Back in the days of Kenne Bell twin-screw 2.8 vs Magnuson 2.3 TVS, the real difference was that the TVS was better efficient to 16psi, and then the larger size of the Twin-Screw helped outflow at anything above that. 16psi is quite a decent amount of power. (old link with compressor maps)

You really can't miss with either, both are legal in all 50 States, both get you over 700hp and well past it, depending on the additional mods/money you sink into it.

Same boat with my 19 GT PP2. Heard the Whipple was better but stuck with the warranty quandary. Definitely pulling the trigger as soon as the chaos is over..

My buddy did the same thing you are doing only he had the 2015 model. He went with the roush packages that you can get in "stages".. He is apparently making around 600hp. All from the dealership. Which I can only assume is covered with its own warranty too probably. Oh and the tuning was done at the dealership, I am guessing like a flash or something.