Bought a size 4 for an almost 3 year old. The pants are a little long but they fit in the waist with quite a bit of stretch so I feel like I'm going to get at least a couple years out of wearing them. I like that the skirt and pants are attached so I don't have to struggle to get my non-pant-wearing 2 year old to put on pants or tights under her skirt in the Canadian winter.
I ended up with 2 sets— both of them gifts. The recipients and their parents loved them but I haven’t heard any details