Hey Juan that is the million dollar question and if you ask 5 different people, you will usually get 5 different answers...so here we go. While both of them provide the same end result of huge HP gains, the are very different on how they accomplish it. First the Pros: TURBO.... provides the most HP with a lower amount of boost, usually does not require a different rear end gear, very streetable. PROCHARGER: Less parts and easier to install, easier to get traction under boost, creates less heat under the hood, easier to tune. Now the CONS: TURBO: expensive and harder to install. harder to tune, create more heat under the hood and takes up more space. PROCHARGER: needs a complete exhaust system, requires a change in rear-end gears.
I hope that doesn't confuse you even more than before you asked the question. Both are safe if installed correctly and tuned accurately.
The amount of boost is not as hard on the motor as the duration and frequency of being boosted. For example, you can boost the car to 600 HP once a month and it would be easier on the motor then boosting it to 450 HP every weekend.
Just a reminder that both systems will require upgraded fuel and ignition systems to accommodate the extra compression.