One of the most discussed topics in the tuning world is turbo vs supercharger setup.
Unfortunately there is no straight forward answer to this. Only answer you could if is, depends on your setup and demand.
Both turbo's and superchargers have there advantages and disadvantages. In this article i have tried to put most of them down, so that it makes your choice as good as possible.
According to wikepedia:
A supercharger is an air compressor used for forced induction of an internal combustion engine.
The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally-aspirated engine, which allows more fuel to be burned and more work to be done per cycle, increasing the power output of the engine.
Power for the unit can come mechanically by a belt, gear, shaft, or chain connected to the engine's crankshaft.
A turbocharger, or turbo, is a gas compressor used for forced induction of an internal combustion engine. A form of supercharger, the turbocharger increases the pressure of air entering the engine to create more power. A turbocharger has the compressor powered by a turbine which is driven by the engine's own exhaust gases rather than direct mechanical drive.
Ok so now we now what they are, time to look at some cons and pro's.
This is where the turbo has the biggest advantage. The turbocharger should be more economical as it operates through energy created by exhaust gases that would otherwise be lost. The supercharger is powered by a drive belt connected to the crank. The turbocharger is not free of inefficiency as it does create additional exhaust back pressure and exhaust flow interruption.
This is where the supercharger has its biggest advantage. Since it is powered by a belt, it always produces boost, even at low RPM. The turbo Needs to spool up its turbine before making boost. which creates lag. The bigger the turbo the higher the lag. Modern turbo's setup, however, have almost no lag anymore.
A turbo setup and supercharger setup have almost the same costs. Turbo setup's, however, have so much on the market, that lots of people can make there own setups for less costs. Also a turbo setup is cheaper and easier to upgrade. A supercharger can change it's boost, by changing a pulley, but there is always a maximum.
Because the supercharger eliminates the need to deal with the exhaust gas interruption created by inserting a turbocharger turbine into the exhaust flow, the supercharger creates no additional exhaust back pressure. The amount of power that is lost by a turbo's turbine reduces it's overall efficiency.
Because a turbocharger first spools up before the boost is delivered to the engine, there is a surge of power that is delivered immediately when the waste gate opens (around 3000 rpm). This surge can be damaging to the engine and drive train, and can make the vehicle difficult to drive or lose traction. A supercharger has no such surge, as it already has boost from very low RPM, there for should cause less damage in the long run. It also is more easy to control.
Because the turbocharger is mounted to the exhaust manifold (which is very hot), turbocharger boost is subject to additional heating via the turbo's hot casing. Because hot air expands (the opposite goal of a turbo or supercharger), an intercooler becomes necessary on almost all turbocharged applications to cool the air charge before it is released into the engine. This increases the complexity of the installation. A centrifugal supercharger on the other hand creates a cooler air discharge, so an intercooler is often not necessary at boost levels below 10psi. That said, some superchargers (especially roots-type superchargers) create hotter discharge temperatures, which also make an intercooler necessary even on fairly low-boost applications.
The turbocharger is generally quieter than the supercharger. Because the turbo's turbine is in the exhaust, the turbo can substantially reduce exhaust noise, making the engine run quieter. Some centrifugal superchargers are known to be noisy and whistle which, annoys some drivers (we, however, love it!) however, some turbo setup's have a very loud Blow off valve. In some cases this makes more noise then the supercharger.
In general, superchargers enjoy a substantial reliability advantage over the turbocharger. When a a turbo is shut off (i.e. when the engine is turned off), residual oil inside the turbo's bearings can be baked by stored engine heat. This, combined with the turbo's extremely high rpm's (up to 150,000rpm) can cause problems with the turbo's internal bearings and can shorten the life of the turbocharger. In addition, many turbos require after market exhaust manifolds, which are often far less reliable than stock manifolds. Last thing to take in account is the surge, which could cause damage.
Ease of Installation:
Superchargers are substantially easier to install than a turbos because they have far fewer components and simpler devices. Turbos are complex and require manifold and exhaust modifications, intercooler, extra oil lines, etc. - most of which is not needed with most superchargers.
Maximum Power Output:
Turbos are known for their unique ability to spin to incredibly high rpm's and make outrages peak boost figures (25psi+). While operating a turbocharger at very high levels of boost requires major modifications to the rest of the engine, the turbo is capable of producing more peak power than superchargers.
Turbochargers are notoriously difficult to tune. Superchargers, on the other hand, require few fuel and ignition upgrades and normally require little or no engine tuning.
This is where lots of supercharger setup have problems. Especially the higher boost setup's that need an intercooler. Since with most supercharger setup's the throttle body is placed before the supercharger, it has a lot of air volume in the pipes between the inlet and supercharger. This could cause idle drop.
To solve this issue most setup's have a dual throttle setup. one throttle body on stock place (inlet) and one before the supercharger. A bov is needed to release the pressure in between.
So for conclusion, we went for a supercharger setup for the simple reasons that it was easy to install, no lag, and less heat. Because we found a used setup for little money, our decision making was easier.
Source: superchargersonline and my own experience.