The definite disadvantage is quality tights. Composition: Cotton 80%, Polyamide 15%, Elastane 5%. According to the assurances of sellers and the manufacturer, this spandex makes the tights stretch well when applied and do not stretch in the wash. Unfortunately - nonsense. Already after the first wash, tights look like they have passed through the legs of at least 4 children, they are stretched so that they hang on the bottom (in one of the pairs the other diaper would fit easily). Pressure-free elastic at the waist does not hold tights, so the elastic hangs on the hips. The feet slip quickly, whereby half of the "patent" races against the child's foot. If we get a better game, we can count on the foot to raise and vice versa. However, the biggest drawback to these tights is the fact that silicone anti-slip on your knees is in fact located in the middle of the tibia. And the size of the tights doesn't matter. I bought my daughter both size 68/74 and 74/80 (she wore 68 at the time). I do not know how such solutions are to help a child learn to crawl, since none of the anti-slips is in the place where it is needed.
However, tights have a few definite pluses. The first is price. The cost of such tights in a warm, winter version is several zlotys (12-15 zlotys) if we choose an online store. This is a very attractive offer, considering that only tights or Sterntaler tights are available on the market, starting at PLN 35 per pair. An additional advantage is the extremely wide base of patterns and colors. Tights are really cute and encourage you to buy. The thicker version is very warm and you can freely release your child at home only in tights, without having to wear shorts.
Given all the FOR and AGAINST, I personally prefer the child buy ordinary tights, at the same price, but better in species and devoid of fancy inventions, completely ineffective. Or I decide to take the risk and invest in a more expensive copy in the hope that this time I will pass the result. In the end, the child will learn to crawl, sit and walk, with or without tights. At most, it will take him a bit more time and effort ...