Infield grandstand seats are OK seats. They are pretty far away from the field for Lower Level seats. There are numerous supports in the way of the field, so you may have to contend with an obstruction depending on where you're sitting. Grandstand 12 is just past first base on the Red Sox side of the field. Seats here are covered and protected from the elements.

View from Infield Grandstand Section 12
Some of the seats in Infield Grandstand Section 12 will have to contend with support pillars for a view of the field