I will start by saying that I did NOT receive these for free or a discounted price. I paid FULL price and this is just my honest experience with this product; I hope it helps you! :)
I bought these booties at the same time as the (much) more expensive Zutano brand and I like these a LOT better than the Zutanos. First, I like that they have little non-skid dots on the bottom. Being that they are fleece, you would think adding these little grippers to the bottom would be standard, but the Zutanos do not have any kind of grippy/anti-slip stuff at all on them. This is an important feature because my daughter is just learning how to free stand and she falls enough all on her own, thank you very much.
Second, I thought that the Zutanos would be better because of the snap closures. Since these have a velcro closure, I was skeptical that they would stay on. However, the velco not only holds together very well (believe me, my daughter tries to get them off as soon as I put them on her and she has been unsuccessful every time) but its actually better because you can adjust them in an almost infinite range with the 1.5" strips of velcro they provide. The 2 snaps on the Zutanos make them 'adjustable' but only with 2 definitive sizes while these can be loosened or tightened however much or little as you need. My daughter is skinny (only 25th percentile for weight) and I can get these nice and comfortably tight around her ankles while the Zutanos she can pull right off because the tightest I can get them is still too loose on her.
Also - my daughter is not a fan of shoes (are any of us, really?), but she seems to be fine with these. As mentioned, she does try to get them off as soon as I put them on her, but after a few tugs she realizes she can't get them off, and then she crawls and stands and plays around without giving them a second glance. Plus, she looks incredibly cute in them!
I've provided some pictures against a ruler; my daughter is 13 months old with long skinny feet and I bought the 12-18 month size. They fit well with plenty of room to grow, so I think the sizing is on point. The bottoms of these measure exactly 4.5".