It's not competitive, there are 3 categories in the Spanish bike championship, 125cc, Supersport and SBK (which they call Formula Extreme).
125cc is the most competitive one, the only one that gets TV coverage, there are many foreign riders from Italy, Japan, England, etc, probably the most competitive national 125cc championship in the world
Supersport is OK, there are some good riders there, but from 125cc and Supersport the next step is the world championship (125cc and 250cc), national SBK is for oldies and the guys that aren't good enough to get into the world championship.