Love having the manual trans. You have to row a 5600. It takes a little time to learn it. DIESELWRKS is right, it can be notchy. I also run the Redline. I was hoping to free it up a bit, but it is what it is. It is no hot rod until you get her rolling. On the freeway you never have to shift.
Sounds like there are a couple of companies that know the 5600 really well. There is a thread in the "911" section taking about one of them.