One of the biggest complaints about orchestra seating is the lack of elevation. Often-times it can be difficult to see the stage behind 25 rows of people. Terrace seating alleviates this head-ache by providing riser-style seating. This does create the need to walk stairs, but with 15 rows per section, the climbs aren't too taxing.
Sections B and C are located in the middle of the terrace and provide the best views of the stage. Like the orchestra, odd seats are on the left and even seats are on the right. However, unlike the orchestra, seat numbers reset as you move into a new section. So there is a Seat 1 in Section C and Section D, with the Seat 1 in Section C far superior to the one in D.