turbocharger > supercharger
yes, superchargers CAN run 50psi. top fuel drag racers run around that area.
superchargers build boost right off idle, being run off the engine. You get instant throttle response. A roots blower has rotors that spin to draw more air into the engine, while centrifigal is closer in design to a turbocharger. A third kind of blower is a whipple, but I don't know jack about those, hehe.
You will find harsher/more regulations for cars with turbochargers than any other power adder. Their benefits/strengths have already been stated several times so I won't bother with them. Except that turbo cars can be docile enough when not into boost that your mom can drive it to the store and not know she's in a 9 second street car
For most of us, however, it doesn't matter
much. Either one can make plenty of power for the street, but personally i'd go with a good turbo system. Turbos can fit in space a SC cannot. Both can make great amounts of power, but for the most part, turbochargers are superior. My Firebird is going to have two hairdryers, my import will have a hairdryer, and anything else I run boost on will have a turbo.