A new model-based plasma current and shape controller has been set up and tested on the JET Tokamak with the existing active circuits and control. The installation has been carried out without causing any interference to the plasma operation, or requiring long commissioning time. Eventually the new controller was used on really extremely shaped Internal Transport Barrier experiments at high poloidal beta and in the presence of quite large variations of the plasma current density profile (variation range Dbpol up to 1.5 and Dli up to 0.5). The XSC controller architecture and philosophy also offer new interesting opportunities, e.g., the separatrix sweeping on the divertor plates without significantly affecting the overall plasma shape, and the possibility of improving the overall tokamak performance via combined control of plasma shape, current and profile. The adopted methodology constitutes also an important test bed for feedback control strategies of ITER relevance.