Wow. What a board...
Anyhow, it appears to me that Opeth have a 9/10 talent and a 10/10 beauty.
The Opeth members are no virtuosos at their respective instruments.
Still, all of them are incredibly good. Lopez being the most talented at his instrument, Akerfeldt being the most creative person.
The growling also takes a lot of talent which Mikael does possess. Akerfeldt is also the guy that writes the best visual lyrics. Heck, they are even sociocritical.
As for the beauty, it's a subjective thing of course.
I however wouldn't say that a few repeats of several (!) riffs in a single song make their music repetitive. Not, at all. You may not like what they play but that's a different matter.
They are also not predictable, either.
The way the lyrics and the vocals are accompanied by the music is unmatched. This was executed the best on MAYH, I think.
They always create the perfect atmosphere for a line/verse/chorus. They always succeed at delivering moods.
It's a shame that even Opeth fans underrate them... oh well..