abrand- Congratulations on going to Spain during undoubtedly one of the most interesting, inspiring times. If you're not completely sold on Cordoba and Granada, let me offer a couple of hidden-treasure suggestions:
1) Valladolid has the second largest procession (Sevilla) in the country on Easter weekend. The procession is marked by a float for each station of the cross amongst many others. The crowds are plentiful, but manageable. The ambience is unmistakable, and it seems as if the entire capital is out for the event. Medina del Campo also is renowned for its procession, and is worth a trip.
2) Camuñas, located in the southeastern part of the province of Toledo, has an incredible celebration in association with Corpus Christi. See the following for more information:
Camuñas' celebration:
http://www.pecadosydanzantes.com/indice.htm Corpus history:
http://www.newadvent.org/cathen/04390b.htm I don't know the exact dates, and I know they're not necessarily the time, but the celebration in Camuñas is WELL worth the trip. It's a small town, and the crowd and auto presented are unforgettable!
Enjoy your trip!