why do you guy's like a turbo vs a centrif Supcharger?

It depends on what your looking for. Me and my brother have had this conversation millions of times. If you want almost instant power you want a supercharger. If you want more efficient power you want a turbo.
IMHO, I would go with both. Twin charging. I know someone said why do that, well if you have ever used an oxy fuel torch, its the same concept. You can turn up the fuel and have an inefficient flame or can turn the oxygen up too high and the flame goes away or you can get the right mixture and have raw, efficient, "heat."
With twin charging you get the benefits of both, you get the efficient-ness of a turbo and the almost instant power of a super.
Also, a lot of folks think that a turbo in built for the motor, I don't think this is true. You can take a turbo for a TD and slap it on a 340 and it will blow up unless you build it right and you can bluild all your plumbing.
Correct me if i'm wrong, please