"there may be some difference in the exhaust theory between the 5.4L and 6.2L motors"
The 6.2L V8 is oversquare, so it revs freely, and will need significantly more flow. I'm ordering a 2012, but I do not intend to make modifications like that. I'll add some fog and driving lights, air horn, emergency lights, siren and fire radio (I'm a volunteer fireman), but owning two F250s and a Bronco (my fifth), I've learned that mods like that are a trade off. I had very fancy headers on a 350V8 1980 K5 Blazer, and I've modded several exhausts. You'll get more noise, probably with a drone (that always seems to occur at highway cruising speed) along with the minor performance boost. For me, the beauty of the Raptor is that you do NOT need to mess with it to get a great performing truck. Best of all, you will not void your warranty. In other words, there's a spectrum of choices, and most of them will make one thing better at the expense of something else. The SVT engineers have done a superb job of making those choices, and finding great balances between noise and performance, with the emphasis on performance, especially high-speed off road performance. I do not know more than they do, and I do not have the budget to try a dozen different replacement systems. Even if you did, I'm not sure that any of them would be a better compromise, and they're certainly not worth voiding the warranty.