I know of them, well.
Their tunes don't seem to be all that great.
And their prices are through the freaken roof.
They do know their 4.6 engines though. But anyone that i know that got a chip done by them, had to go back at least once.
When my buddy does 4.6 cars, because of the lack of a dyno at his shop, he has jdm do chips. Too bad as i said, they all go back once or so. He also does the work itself fairly cheaper than jdm.