The gig on the 11th is like the biggest thing happening this summer, atleast if you're talking about individual gigs since there's 4 big bands playing that day; Cult of Luna, Evergrey, The Haunted and Hammerfall. We're talking about 3 local bands there so you'll have the pleasure of getting packed with the true fans of the bands.
There's a festival thing going on in Gothenburg during that period so I'd try to check the different demostages for some metal underground action. I mean, it's not like you're gonna get anything that's worse than what your used to from back home...
And oh, I can't say that I see any reason whatsoever to go to Stockholm, really.