Madrid isn't the best example of a modern Metro design. BIlbao's one it's far more modern and less 'oldish' and claustrophobic. That was my experience in Madrid. Once the Metropolitan Bilbao area's metro expands further around the region, it will be the best example on how a modern subway should we made.
If only the rest of the western world could do this imagine how much better it could be to live in large cities...