a friend of mine from new england was driving through georgia on a road trip and he ends up getting pulled over for speeding. the cop goes "son you were goin 80 in a 60. no one goes that fast through georgia." my friend responds with "well, Sherman did"
no-there really isn't any need to. It's more of a trendy fad than a functional thing. The difference between a cm or two wouldn't be noticed.
I mounted my Chronics at recommended, and they kill it everywhere. Then I mounted my 1080guns at +3cm mostly because they're a little longer than I'm used to. But I think it's dumb to have them center mounted unless all you're doing is urbans etc.
There are things worse than death, and I can do all of them...