"Generator" is really a high-level place to stay. Although I've chosen the hostel option, it all is designed in good hotels traditions: tidy, modern, thoughtful to details. Great design, nice and helpful reception, awesome location in a few steps from Gran Via which is one of the main arteries of the city.
The only things I was mad about were in common area: too intense sweet smell and too loud music in the lobby, so it was really difficult to have there calls or just work because of the severe headache caused by these factors. In room it wasn't enough of light because window faces the inner square area of the hotel. Didn't find basic things like abbility to have free water to drink (only vending machines - ok, but water is smt very obvious). Opportunity to keep luggage in lockers is good, but for the guests it could be for more loyal cost.
Still, would recommend for the short-term stay. See you next time in Madrid!