The thing is that most of the plants are about the same age if they are in the same group. So, a plant with big traps is the same age as a plant with small traps. Depending on if they were indivually t/c'ed from seeds or are from the same plant, it can either mean the bigger one is healthir, or if from seed that the plant might just have the genes for big traps, while another plant grown from seed might have the genes for small traps. It's like people, there are tall people and short people, some fat, skinny, darker, lighter, ect...
So it's mainly preference.