Arriving as it opened, we largely had this massive complex to ourselves. Not that there weren't other visitors, but the structure swallows you in its vastness and very quickly you can find yourself completely alone.
The highlights are surely the painted ceilings and the royal crypt. Both are stunning in their detail, yet they are also more than that. At certain intervals they produce a feeling of grandeur that demands silent attention. I could not help whispering in the crypt, though I need not have since we were alone. Perhaps, if I was more religious I could better explain it, but the artwork and scale remain with you long after you depart on the train back to Madrid.
We enjoyed our visit, but were also surprised that it did not take longer. I believe we spent 2-3 hours exploring. The garden is fairly standard as far as European royal palaces are concerned. Once we finished, we grabbed a bite to eat before heading back. The nearby street, Calle Floridablanca is filled with excellent places for food or drinks.