In fall of 2018 I purchased Movistar SIM in Seville, daughter went with Orange.
Movistar offered 28 days for 15e, coverage was good but no grace period, and when it came time to renew, ( we were on the VLDP) , their stores are few and far between. If you are from North America, you cannot do an automatic top up, you have to find a store and get it renewed. My renewal stopped working three days later, when I finally reached a Movistar store, they concluded their clerk who did the renewal had not done it properly, but refused to fix it without me paying for another renewal. Not impressed. My daughter had a seamless experience with Orange, but there were a few rural areas, particularly north of Salamanca, where she had minimal or no signal.