On PDB, I think the main strip will always be busy now that you have Hi and Ushuaia. Places to pre-drink, places to drink after Ushuaia while waiting for the taxi queue to die down. We stopped in a few bars on our first night, it was about midnight, everywhere absolutely rammed. Needed to go to the toilet downstairs in Murphy's....absolutely jam-packed. Couldn't move. And it was playing R&B....
But that other area near Octan really is really run down, loads of places closed and rotting away. If you are not staying in PDB people don't even know it is there...get dropped in a cab on the main strip and don't venture further afield. Needs a bit of regeneration...