^COF are not a band, like Slipknot, they are a circus. If you want to feel more mature for liking them go ahead (and yes, I am in my 20s, 21 to be precise), but I wouldn't want to have to endure them with Bodom, there's nothing from them that holds my attention, plus I don't like the circus part of all the dressing and that shit. Maybe I'd respect them more if they didn't do that, but since we can't know and their music doesn't appeal to me at I'd rather not see them, let alone for a full gig time. I had enough of that co-headlining with a band I don't like when Vader came with Marduk. Enjoyed Vader a lot and then got utterly bored by Marduk, plus really annoyed by their tones, I can't belive they make the equipment they have onstage sound so crappy on purpose, I guess black metal is not for me.
Also, for real band I don't mean big, I mean that it's not a joke, and they've toured with Slayer, LOG, Cannibal Corpse, Amon Amarth...
E.g. on the crappy supporting bands, on their 2006 European tour they had as opening act One Man Army (decent, entertaining enough for the 30 min show they got and good sound), but then they got fucking Ektomorph, which was like listening to an hour-long Sepultura's Roots Bloody Roots (the song, not the album) rip-off at waaaay to high volumes. Thankfully enough LDB's intro quickly erased that memory. Then on the Blooddrunk tour they got CC (a bit weird to see as COB's opener but still a great band, glad they got them) and Diablo, which has to be one of the most pleasant surprises as opening act to me (great sound, cool songs, knew how to move the public and put up a good performance). Ektomorph is way more known and big than Diablo, but I'd take Diablo over them any day, that's what I mean with touring with real bands.