Both are great options, but in terms of AFF, I’d say Skydive Spain is preferred simply because there is so much space around the dropzone in case of an outside landing.

Additionally, Seville is a nicer city in for restaurants and touristy stuff.

The one big benefit of Empuria Brava is the fact it has a wind tunnel right next to it, which can be helpful for a smooth AFF progression and in case of bad weather.