I can help you! I've been in the Dali and Velasquez lounges.... Velasquez is the flagship and it's located on T4S. Showers are excelent! I have more pictures if you need of the shower per se. They are a bit tiny in space, but very private. Velasquez lounge is superb at night and when it's almost empty. Had a good shower experience, here are the pics. Amenities are by Melia.

Dali is more.. a good lounge but not the Flagship experience.
Velasquez pics: