I bought my WS-2000 off Amazon because of their return policy and AW's high shipping fees. If I ever needed to return anything during the 1 year warranty, the slightly higher cost on Amazon would be worth it. As far as the 3rd party warranty, it's not really a 4 year warranty, it's 3 years, covering years 2, 3 and 4 while the manufacturer's warranty covers year 1.
I wonder why Square Trade wasn't used? I've heard fairly consistent ratings from them at least.