I rely on my screw gun in my business, so I get one that I can depend upon. Therefore I vote for Porter Cable "hands down"
The "machine gun" screw guns have NOT been perfected and a Hilti dealer told me that. When the bugs are out, I will get one for the building of decks. They are working on an extension bar that allows you to screw screws into the deck while standing up. What a treat. Most of the guns nowdays you have to put the drill almost to the surface.
A 14.4 Porter with two batteries, charging table, case and a clutch will run about $175 at a home center. For the occasional diy, this tool will out last you. For me, they last about 5 years which I use mine every day.