Physical appearance? Check
Everything else? Plant wins easily
This is one of those mindfuck comparisons.
I think Akerfeldt is a far more interesting musician than Plant.
Hell, even Jimmy Paige. Which is bizarre considering Paige is widely regarded as one of the five most influential guitar players of all time, due in no small part to writing some of the greatest, most influential songs of all time. The band from which he is most famous, Led Zeppelin, is widely regarded as one of the greatest, most influential bands of all time.
But here is Mikael Akerfeldt, who is not that influential a guitar player and who has not written influential songs, from a band barely on anyone's radar, and I think he is a far more interesting musician and songwriter than either.