TX springs have been kindly supplied by TX Keyboards, a Korean-based company that provides high-quality springs at an affordable price. Due to the quality control extent that TX Keyboards has gone through, these springs will not have a deviation outside of -1/+1 for spring weight.
They have provided a wide variety of spring weights; the force of these spring weights is measured at bottom-out. Differently-weighted springs will feel different depending on what type of switch they are put into, and it is important to understand that it can drastically change how the switch performs.
The difference in the spring length will affect the initial force for the keypress, but does not affect the bottom-out weight. So, the 16mm springs will have a higher initial weight than the 14mm springs, but the bottom-out weight will be the same on both.