Build quality is great. Mine still works perfectly, without a plastic chip or anything even after tens and tens of drops and hits. And it is just absolutely wonderful, one of the best mouse on the market right now, if not, the best. Its the best Razer product created imo.
On the other hand, the Blackwidow is another story. Cos it has a poorer track record compared to the DA. Do consider the CoolerMaster Quickfire if you dont mind different Cherry switches, or the Rosewill Mech.