Had these seats this past weekend for the Reds series. Had a blast and 318 was an excellent choice of seating. We arrived early and took a stroll around to see the sights and listen to the sounds. There's just something about hearing the crack of the bat and the aroma of Italian sausages at this place. Plus, they have a Quaker Steak and Primanti Bros. on site.

Anyway, 318 would be a great choice. You're going to spend a little more for these seats than the other grandstand seats because they're kind of behind home plate but more towards the third base side. Perfect view of the Pittsburgh skyline from these seats.
These seats are obviously going to be more comfortable than the bleachers. But if you want to sit close to the field and are willing to sacrifice the view of the surrounding area and a little bit of comfort, than the bleachers are the way to go. It's not that unlikely for fans to find $5 bleacher seats on the street. z