I have the skirt in a 6 (which is my true size at most places) and it is snug at the top, but it doesn't give me muffin top or anything. It does stretch a bit though. The first time I wore it, I had to pull it down a lot (it liked to work it's way up my waist). I have yet to encounter a denim skirt that doesn't do this, though. After the first wearing, this stopped being a problem, with only an occasional adjustment to get the seam in the center. I only wash it on cold maybe every 3 or 4 wearings, since it doesn't really get dirty (I'm indoors on chairs a lot), and it's not quite hot enough here that I'm sweating a lot, either. I air dry it, and it hasn't faded at all.
Maybe you should post some pictures of you in both skirts, and we can help. It does stretch though, but I wouldn't say it gets really baggy, just comfortable. On me, the waistband sits right below my belly button, I think.
