It's ok. because it's the best site for data in English right now
But i don't have problems to write Spain's 4G/LTE situation on this forum again: 4G/LTE is only available in major towns so far.
On prepaid it's only available for a surcharge on the network operators, not the MVNOs.
movistar and orange: only for contract plans; Vodafone: on some Yuser prepaid plans. Yoigo: on one prepaid plan so far.
You need to know that you pay a big surchage for 4G/LTE in Spain on PAYG so far. Better check before, if it really is available at your specific location.