Wx's are the entry level model to compete with Rockford Fosgate's Prime line and similar cheap/stripped down offerings from other big name companies, W0's used to be the entry level models until the wx's came in and w3's are the middle level models. The v at the end is the version # and the higher it is the newer the design with v3 being the most current. It all comes down to marketing, price and overall output. I would avoid the Wx's.