Quick in a positive way.
Guard with leather armor around the corner. Character surprises guard and rolls 15 with Ranged bonus +3. Arrow deals 5 points of damage and guard has 4 health points. Arrow travels through guard's back and bursts his lung.
Another guard is coming and character hides next to corner. Surprise with rapier. Leather armor doesn't help with another 15 roll and 7 damage is enough to kill the guard as he is passing by.
This took only 11 seconds because we already knew how it works.
This I call adventuring. It doesn't take five minutes to consider all those options before even getting to roll etc.
This was fast, simple and brutal.