Performance wise, they're pretty much the same. The general rule of thumb with exhaust is less bends = better, but mandrel bends pretty much eliminate that.
The sound isn't going to differ that much either. It really depends on which mufflers you choose
2002 Mineral grey GT 5 speed. Flowmaster 40's catback, Mach 1 grille delete, timing advance, push button starter, Bullitt pedals, FR500 steering wheel, K&N FIPK, Self ported upper intake w/ spacer, Pioneer Avic D3, MGW shifter, MM FL subframe connectors, Mach 1 springs, Bilstein HD struts/springs