[SenorFunkyPants]

Like the OP I own a DCT....in his position if I thought I might like to make the change to a MT, I would test drive it and then make a decision. It wouldn't occur to me to let a bunch of random people on a forum influence my decision...Sure if I wanted a recommendation for some aftermarket tat then no harm in asking - but the transmission, really?
The MT has consumable parts while the DCT doesn't, the MT's clutch and flywheel are both parts that will almost certainly need replacing once (at the very least) during the cars lifetime. The syncromesh rings also seem a little under engineered given the number of 1st to 2nd grind complaints and may well not last the life of the car.
The Getrag 7DCI600 DCT is rated to handle 600nm (the M3 produces 400nm) so there is plenty of headroom. There is no pattern of hardware failure or parts wearing out in DCTs. True if something goes wrong it will be more expensive but that is why you buy a warranty.