If memory serves, I do not recall any major obstructions in the Walter Kerr orchestra section. Steer clear of the balcony though. I sat there once for A Little Night Music. I am not a huge person, but the seat in front of me was slammed straight into my knees and the arm wrests were digging into my sides (plus they had the heat set at inferno at the time, which did not help matters). This seemed to be a problem for a number of other people up there as well.