not sure about airbags going off, it's the legalities of BL'ing an airbagged vehicle.
the 2.5L V6 in the later GV's (SQ625) put out 30+ kw more than the most powerful Vitara V6 2.0l (SV620)... pretty sure the looks are the only downside.

the rear diff is essentially the same in the GV, apart from wider track & being a 5 link suspension design compared to the Vitara's 3 link.
the 4 speed auto's are the same in the GV's & Vitara's (early carby SWB vitara's had a 3 speed trimatic) & extra cooling is a smart thing for any auto working outside of it's design parameters. EG larger tyres & being worked hard offroad.