lined ones should always stay the same length, and not stretch. with ordinary ones the side you always get up on stretches and just a little bit off is enough to put you off balance.
lined ones are thicker so might create an uncomfortable bit under your thigh.
I just have regular ones and try to swap them over when I'm cleaning the saddle and I get up both sides anyway. they are fairly old now so I will probably replace them as the buckles have worn where they sit.. my legs are still the same length so I can't change that! lol
regular ones tend to be cheaper , lined ones might last longer.
i am fed up with the speed and the greed of the world around me but i have not found nor can i offer a cure