I stayed at Revolver for four days when I visited Edinburgh for the first time and the location was, in my opinion, the best thing about it.
I booked a bed in a "premium" room, but upon arrival, the bunkbeds looked nothing like they did in the photos, and my bed had clean sheets on but there was a very dusty-looking decorational cushion on top of my pillow, which I didn't appreciate.
There was a kitchen in the basement with a fridge, stove, etc. which I never stepped foot in and can't comment on. The showers never seemed to be cleaned the entire time I was there because the same towel and empty soap bottles were lying on the floor from the moment I arrived until I left four days later. The floor in my room was also quite dusty and dirty - never saw a cleaner during my stay. A nice plus was the vanity room with hair dryers, a hair straightener, good lighting and sinks.
I received a key card for my room but almost never needed it because the door was barely ever closed, which felt a little unsafe.
I probably wouldn't stay there again unless I booked a private room with its own bathroom since the location is fantastic.