Do you know many of the Adapter selling online "looking like Original" one are actually Cheap copy?  Most of them selling almost half price as the Genuine one, but do you really think you can buy a Genuine one for almost half price without problem?  These people only make the sticker on the adapter looks like original, but the adapter's quality are always very poor because large portion of the production cost goes to the sticker!

 

If you can afford to buy a Genuine one, it's better to buy a Genuine one, otherwsie if your budget only allows you to pay half the price, there are many of the aftermarket brand one are in good quality as the genuine one.