I own a copy of Ainadamar on CD. My non-Spanish ears found it rather compelling, although I understand (and share) the flaws you've mentioned.
The life and poems of Gabriel Garcia Lorca, whom I admire so much, are a good operatic subject any day. So, I rather liked it, a lot. Seeing it on stage is a dream.
Peter Sellars is a most interesting individual. I have a lot of respect for him. I hope I'll catch him one of these days for an interview.