I'm of the opinion that Suzuki have researched the gearing and given the bike the best balance of acceleration and economy.. Having also developed the engine in conjunction with the final drive I'm not about to second guess their R&D..
However, most of my riding takes in all riding situations and environments so I need that balance, if you only do motorway miles then there's merit in changing the gearing.. There is a school of thought that suggests that, as GW states, a drop in revs at a given speed due to higher gearing means the engine is working that bit harder at the new, lower, rev count and consequently uses more fuel, cancelling out the perceived saving due to the lower rpm.. I'm no engineer so I wouldn't want to state this as fact.. It makes sense though, after all how can you squeeze more energy out of the fuel, thereby using less for any given speed, with the same powerhouse?