Good experience.
I had a mixed impression of Skippy website, as information on returns is very hidden and the website doesn't seem to be updated very often (for example, on january 12th it was still mentioning return terms valid until january 10th).
However, after ordering, I must say the experience was great. Onesies feel comfy and soft even after two washings. I bought 2 sizes because I was uncertain, and the return process was also flawless (after finding the link for returning which was very hidden in the website, everything worked great with fast processing and refund).
Small note, we got two different types of onesies of sizes M, and one of them fits perfectly while the other one is definitely too small on the same person. If you are in doubt, I recommend ordering two sizes and trying both on as I did.