Not surprisingly, the limitation of shooting exclusively with the "P" mode should now become pretty clear. At times, it just doesn't cut the mustard. At a review on the more popular shooting mode, it is true that Aperture Priority receives the greatest appeal.
In fact, only 16% of the crowd prefer Program Auto mode! To fully understand the appeal of the "A" mode or "S" mode, it is recommended you shoot exclusively on that mode for say a month. No amount of written guide can give you that feel you require.