I disagree that -1 in the front equals +3 in the rear. On a gearing chart sure, but consider that +3 is using more of the same power lower down in the rpm, thus feeling like the engine has more torque. Going the -1 is actually being able to use less of the torque the engine makes, for example going from an 18 to a 17, imagine going from an 18 to a 3(theoretically).
That 3 tooth couldn't utilize the engine's torque and capabilities. Going down only -1 of course is no where near as dramatic a change, but still noticeable to the same effect.
I have changed front and rear gearing on many bikes and I have an 08 Gen2 Busa now.
Gen2 stock gearing is 18/43, I have tried 18/46, 17/46, and 17/43. My personal preference is 18/46, just +3. The 17/43 and more so the 17/46 made the Busa feel more like the GSXR1000, higher, faster revving, with less bottom end torque. As obviosly close in power to weight ratios the Busa and 1000 are, the Busa's bigger engine was designed to be more tourquey as a sport touring street bike.
The Gen1 and 2 gearing are different as is the power curve of the engine, but the principle is the same. Gearing charts are a good source of information, but are taken to be 100% accurate, where as they will only get you in the neighborhood. Math never changes, but there are too many real world elements to take into account. Temperature, humidity, elavation, ect. all cause changes in any engine's performance, and all engines are created differently to perform for a specific function. This would explain why different engines/applications require or use different gearing. This is also why the same gearing change can not have the same effect on every engine/application. -1/+3 is common and commonly misunderstood as -1 = +3 and vice versa, in the real world it doesn't.
On either Gen1 or 2 you have room for -1, +3, or both with the stock chain and still have plenty of slack for adjustment. The Gen 2 stock is 18/43 and 144 link chain and the Gen1 is(someone correct me if I've forgotten)17/40 and 142 links.
Sorry to have rambeled, I hope this answers any questions.
And just +3 is alot more wheelie happy than -1, or -1 +3, that's real proof