[Book spoilers] Winning or losing on location visuals?

[Northern Soul]

I'm trying to figure out if we're getting a good deal or short-changed on seeing the fortresses/castles of the great castles.

Seeing Pyke, both on the credits map and the exterior during the episode was awesome. Looked perfect.

Harrenhal also looked great, much creepy than I imagined from the books; who'd want that as their seat? (Also, I noticed Harrenhal didn't really 'move' on the credits map - is this to emphasize how moribund the place is?)

But on other areas we're missing out. There's been no external establishing shots of Dragonstone, which seems bizarre as it seems to get described in book world as arguably the most imaginative castle in the story so far, not just another holdfast.

Also, have Riverrun and Storm's End basically been cut out of the show completely? I feel these locations are important not just to convey to the audience where characters are - e.g, Riverrun = rivers = ahh, yes Robb is somewhere around the riverlands - but also for plot reasons. E.g why is Stannis at Stirm's End if there's no Storm's End?

I understand there are visual effect limitations, but if we're going to see places we really should get externals for context?