Incredible to live with Gratal almost on the doorstep and I still haven't done it. Ricardo has (from Arguis), so its not on the top of "our" list.
This spring we set off from the south side - Nueno, via los Gorgos Negros & Ermita - following a route in a shiney new guide book that Javier had given me for xmas. And we couldn't find the path above the barranc! We had 400m of ascent still do do!
This face is interesting (and there is no ugly pipe to follow!) but its not for a very hot day - and better if you can find the path!
Peña Gratal is an interesting peak and we were lucky with a sunny day. We climbed from Embalse de Arguis and we walked to Pico de la calma (1584m) descending across ravine of Las calmas in 5h.