Personally I love Friden's vocals in R2R, as well as Colony and Clayman....I can only speak for those coz I don't have their other albums. Contrary to what a lot of you seemingly metal purists are saying I think his clean vocals are good on R2R, namely Dawn Of A New Day, coz admittedly Metaphor is a bit too......weird.
You say an accomplished vocalist should be able to do clean singing, but Stanne isn't exactly the greatest......unless in their next album there's some clean singing and he's improved on Projector's vocals.
I might as well say what I listen to, seein's that would probably explain my point of view.
Dark Tranquillity, In Flames, Arch Enemy, Soilwork, Moonspell, Lilitu, Corporation 187, The Haunted, Naglfar, Withering Surface, Detonation, Forest Stream, The Duskfall, Sentenced and Rakoth to name a few 'metal' bands, plus less heavy stuff like Lacuna Coil, Entwine, Without Face, etc.
BUT I'm also into the more commercial side of rock/metal, bands like The Used, Ill Nino, QOTSA, Hopesfall, My Chemical Romance, Evanescence, Disturbed, Audioslave, RHCP's, etc.
All of these in my opinion have talented vocalists in one way or another, but I'm sure you'll all disagree.
I would say that Friden has as much variation in his vocals as Stanne, but on the basis of vocals I'd much rather listen 'Dawn Of A New Day' then, say, 'Auctioned'.
I'll stop there, I'm just rambling, but yeah, I like Friden's vocals a lot.