So basically if you want a bulletproof motor that will last 150K miles, has great power, and is extremely rideable, leave it stock. Any gains you get from changing the stock Busa are going to have some sort of draw back. I'm not an expert, but here's my assessment:
1. Turbos are for going straight really really fast. They are an efficient ($$$) way to get big power and can be fairly reliable if the bike is built by a knowledgeable builder. But they also radically change the character of the Busa as you need stretching and lowering to handle that HP effectively. I think the turbo is the perfect drag engine, but can be ridden daily on the street.
2. Superchargers are more rideable but are complex and a bit heavy. They do not offer the HP gains of a Turbo and their power is a bit parasitic, especially on the low end. However the power is pretty usable and lower in the range than turbos. I can't see going for an SC to drag race, but it can be used as a daily rider. SC reliability is probably at question as there are a lot of moving parts added to the intake side.
3. Nitrous shots will get you some power, but apparently a the expense of making the engine consumable. It's also only a quick boost in power and requires filling a nitrous bottle and keeping it relatively cool. Not my thing even if it's pretty cheap.
4. All engine is the best option IMHO but there are some considerations here too. The first and biggest is that the isn't much HP to get in this way, maybe 200 to 260 or so. Worse, to get 260 on all engine will cost as much or even more than a 300 HP turbo kit. Big displacement brings heat, and can make your Busa more fragile than either a turbo or a SC. I have been told that big power usually moves the power up in the RPM range. SO IMHO, all engine is for those who want a little edge in power and the bragging rights against the new liter bikes but is still not looking to win legal or illegal races. Oh yeah, you need to be willing to spend $5K to get 240 hp (assuming you don't do the work yourself) for this little bump.
So I wrote this to start a fight
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. But I think a good discussion on these options would help a lot of people here make decisions on the mod path of their Busas.