The only one of which is a somewhat serious concern is the short cord?! So the bottom line is that the Huawei proprietary system is best, but you can also buy generic PD charges and it will work just fine. Although the padding gets a little uncomfortable after long sessions. I ordered these for my 4 year old who is in a size 11. Bought these for my son to wear at the beach. Fit fine. My son loved him and he now uses them. They are just so pretty and soft and useful! Great purchase, have 60 miles on them now and theyre great. This towel bar is not very sturdy.