It is just single piston, but dont let that fool you. The discs are 345mm and the brakes are very much up to the job of stopping the car. They are better than the Brembos on the LCR and cheaper for parts too. Take a shot of a MK2 LC to see for yourself.
I think the brakes on the cupra are over assisted which gives the feeling of being powerfull.
I only think seat stayed away from brembo was down to internal politics and cost, they have just used the parts bin from other models.
The brakes on the corsa i drive are over assisted too and 'feel' more powerfull, but there is little feel to braking.
The 4 pot brembo which is a very ridged caliper is in my opinion better than a single piston sliding caliper which will suffer from flex and heat.Why do all makes of cars which want to uprate the brakes look to multi piston fixed calpiers for increased performance, from the likes of AP or Brembo it is always multi piston.
I dont think the brakes on the cupra were a step forward from the LCR, more a cost exercise from seat despite what they said about the brembo's.