Most seamless gutters can be matched color-wise to fit your home and are more secure compared to non-seamless gutters. They are sturdier and provide a better deterrent from critters trying to get into them, and fewer seaming means less leaks.
Sectional/non-seamless rain gutters are more traditional. They will last for years, a positive about these types of gutters is that they can be replaced within sections, as opposed to the entire technique. In order to have them live up to their full potential they will need to be properly managed, which includes regular cleaning.