For those of you Yankee fans that still haven’t been to the new Yankee Stadium yet, the Terrace seats are what was previously known as the “Tier Box" at the old Yankee. Seats are much more comfortable now with more elbow and leg space for fans. The grass seems greener but the fan atmosphere isn't what it used to be.

Each Terrace section has between 7 and 10 rows total. Each row has between 19 and 25 seats per row roughly so it's fairly big in that regard. Shoot for the aisle seats.
312 is close to both the infield and the outfield down the first base side. Right in the middle so you can span the entire length of the field with your eyes, no problem.
We saw a good bit of foul balls hit the Terrace level but none near where we were seating. I highly recommend section 312 for fans that want to just avoid the Grandstand and have a decent view of the field without completely breaking the bank.