Irrespective of the general 6MT vs. DSG arguments, the one thing you can't get around is that, judging against other transmissions in the same category, the R's 6MT drivetrain is mediocre, whereas the DSG is fairly decent.
The 6MT's main problem is the weak clutch, but nobody would ever claim the shift action to be best in class either.
The DSG's only real problem is that its factory programing, which is too eager to reach a high gear and quite reluctant to downshift, is out of step with the R's character. It's also worse than the dual clutch programming in other VAG cars I've driven extensively (Tiguan, Audi Q5), and not nearly as good as BMW (M2, M3, M6). Fortunately this can be much improved with aftermarket TCU programming. Or by rowing the flappy paddles yourself.
So for this car at least, the decision isn't so much between 6MT and DSG as a matter of personal preference — or principle! — but between a substantially flawed 6MT and a pretty good DSG.
By the way, I'm a lifelong stick shifter who bought a DSG Golf R — although not for the reasons outlined above, which weren't generally clear at the time I bought my 2015 R. I also had, and still have, an M3 track car with a 6MT, and thought I'd explore the newer technology's benefits with my daily.
Like i said that's "your opinion" for me after i did my upgrades the feel of my shifter is actually pretty good, to the point where i have gotten 4.0s to 0-60 (stage 2), yes its nowhere close to a dsg but for me that's quick enough.