I always enjoy Carlos Lago's reviews. For me personally, I haven't had the opportunity to drive a 6spd manual F10 M5 yet, but I am planning on it one day. I can instead only speak for the 7spd DCT, and I've used that transmission in all regimes including on the Nurburgring. I think he made several good points, like why would you put a 6spd manual in a 458? Which coincendentally has the same horsepower as the F10 M5. I'm not saying that rowing through the gears wouldn't be fun, but I think the 6spd manual in the F10 M5 doesn't really seem to match the nature of the car.
For me I just didn't want it because of the layout of the buttons in the lower console with the 6spd manual compared to the 7spd DCT. I also knew how incredible a DCT is after driving an M3 with the DCT a few times. It doesn't sound like BMW is even going to offer the 2014 F10 M5 with the 6spd manual either, what does that say about it? I bet there were fewer than 10% of 2013 M5's that were ordered with the 6spd manual for the American market.
Give a man a fish and he eats for a day, but give a man an M5 on the Nürburgring and he smiles for a lifetime.