To me, melodic death metal at its best seems better than brutal death at its best. Of course, I prefer regular death metal (ala Human or Altars of Madness) to either. I don't listen to a lot of death metal these days anyway.
I don't know why, but those pig-sounding vocals really turn me off. When I listen to black metal, no vocal style really bothers me, except for banshee screams (Silencer), which are far from the norm of the genre. (There are maybe five notable bands using that style). Deep vocals like Demilich do not bother me in the slightest, but I just don't like the pig vocals.
Musicianship is not an issue at all, as just about any genre is rife with bands that play exceptionally well, and others that do not play notably well. As for clone/unoriginal/bad bands, I do not think any genre is any better or worse than any other in this sense.
I will listen to the essential brutal death albums someday, to see if I am indeed missing anything, but I strongly suspect this is not the genre for me.