It's pretty seamless. One more skill to learn. The DCT will be easier obviously but I love rev matching my own downshifts. My race car is 5MT and it's very easy to use (and we have to use the 5spd manual box anyways so it's good to practice on my other vehicles).
M3 Sedan - AW/Black - 6MT - no moonroof - no folding seats - RAC RG63 - clear bra by Omega Werks