Pre ordering with amazon? What are your experiences? Nintendo 3ds?

Hi i realy want a nintendo 3ds and think amazon is a good price but is it safe to pre order off them? Would i recieve it the day it launches? Do they take orders until they have enough for the stock they are recieving or just continue taking orders? Would i be safer just going to a shop and buying one on launch day or just pre order it with argos or a well known computer shop. Advice would br grateful as ive never pre orderd before. Whats ur experiences. Thanks