Madrid is a difficult place to find a hotel with a good view.
The Auditorium is on the airport perimeter to the South of the airport, just by the A2. It is a short taxi ride from the airport - there is also a reasonably frequent shuttle bus which I used to return to the terminal.
There are reasonable views of Terminals 1-3, but no view of Terminal 4, which is quite a distance away. All runways are visible albeit at a distance, especially the two north runways, but I had no issue seeing inbounds on 18L / 18R with my trusted bins.
Some of the hotel rooms have an exterior mesh cladding over them which would spoil the view significantly, but it was quite easy to ask for a room with a clear view, the reception staff completely understood what I wanted.
https://maps.app.goo.gl/uGUEdBtE6bxGHBxr8
I ended up with room 2106 which is circled blue in the picture above. To my left, rooms 2107, 08 and 09 are also without the mesh. I would have liked a higher floor, but the first floor was adequate.
The view of T1-T3 from the room is below:
The hotel (including its conference centre) is massive, and there are several food choices, but I struggled a bit after 2200, so if arriving late, please come prepared with food.
