Superchargers is instant, but at the cost of some horsepower
Turbos are free horsepower. Personally I like superchargers, always have had them on all my cars, all BB, no replacement for cubic inches.
Here are a couple of my privious hot rods, both 521 Fords, lencos, 1 and 2 blower combination, 1000 hp 1500 hp.
Unfortunately there is no such thing as free HP. The restriction of the turbocharger stiffles the flow of exhaust and there is your penalty. However, the benefits of turbocharging are greater than those of supercharging when you consider the reduced complexity of the systems.
Yes there are some newer turbos out there with much ilghter weight and variable vane turbines which really decrease their reaction time - but along with that comes other complexity which may challenge durability.
Blowers have their fair share of problems also. The increased wear on crankshaft bearings on the drive end, striping of keyways, fracturing of cranks etc.. Then there is the pacakging issue as well as the challenges of intercooling for supercharged configurations..
Both have their challenges in ignition controls and fuel management..
There is no such thing as a free or even cheap lunch here..
Picture is of a Nova I built. 800-1100 HP depending on Carburetion and under/overdrive of the wheezer..
Believe me, as a ground-pounder, this car made a rather nice statement...

