Personally, I have shopped from almost all of the famous Chinese stores and Banggood.comis one of them! Banggood is reliable and safe as other known Chinese shopping sites likeAliexpress, DealExtereme and Gearbest.
It’s not about only smartphones, whatever you buy, it is safe from Banggood. The products generally delivers with 60 days, sometimes it’s with 15–30 days. But, if you don’t receive the products, the chances are its lost or the Duty officers did something tampering with products! However, you can always contact them, they are quite responsive, and in case of lost or DOA ( dead on arrival) , they do refund! So, it safe to say, buying smartphones or any products from Banggood is safe!