I followed the reviews to a T when deciding to purchase this skirt. Exactly as others have said the XL is really good for anyone 5'8 and under if you like the very long flowy skirt. Its good for 5'9 people who don't really want it dragging the floor or to wear it with sandals and flats. I'm 5'9 and it landed right on the top of my feet with It settled low.  It will not get caught under me while walking and it still has a pretty flow to it.
In my opinion, it's thick enough that I don't need a slip underneath. It becomes more sheer around my ankles. Also I agree with everyone mentioning the tightness of the skirt. I'm a small/ medium and its pretty snug.

I gave it 5 stars because the skirt is beautiful, just not the length I preferred. I bought the XL because the 2XL only had pastel colors. I plan to wear it soon and if I like it and more 2XL come in stock in darker colors, I'll purchase again. I would like to wear it more high waist.

Update 2/20/18- Excitedly wore my skirt this past Sunday to church. I loaned it to my little sister who needed to dance at the service. It was absolutely beautiful as it flowed while she danced. She is about two inches shorter than me so it was looking enough on her to flow. Will definitely be getting an XXL when more colors come in.