Exactly. It depends on just how good a job somebody did in making the actual orchestration of the reduction.
That said, I recently went to an M2 performance at Stanford University's new Bing Concert Hall that was very much an, 'in your face' type performance. The hall has a big stage and relatively small audience capacity. Not once did it cross my mind that the symphony could have sounded better with a reduction in forces. In fact, my thought was, "Mahler would love this".