I have two Porter-Cable guns - an 18ga headless pin and a narrow crown stapler.The stapler leaves a larger hole to fill, but seems to make a far stronger connection (2 pins for the price of one?) and combats torsion.
The 18ga pins in the longer lengths have a nasty habit of popping out of the joint at right angles to the drive axis - can't decide if it's poor technique or if they're susceptible to deflection.