M Patterns are buy setups
W Patterns are short setups
Pattern alone can be one component of a system, others can include - anything! I like Multiple Timeframes, Support/Resistance, Cycles, Relative Strength, Volatility, %R - and others.. System design is wide open really.
The main advantage with the patterns is for programmers - they can 'get hold' of price levels via patterns that aren't identifiable as important through any other method i know of. Test patterns exhaustively, that's exciting. If there's an edge, which i believe there is here, it can be found scientifically.
Here's a system idea for you: 1hr ADX early trending, Enter on the first Corrective Pattern (uptrend look for an M) on a 2m-15m Chart. Risk 0.5% per entry, enter on a 25% retrace of the pattern. Trail out or go for a 1:1 target (meaning trend prior to correction on 2m-15m, take the price range, and then project that range from the entry pattern D point to give you an equality target, or go for 62% instead of 100%). See if that has good metrics for you. Sounds like a winner to me.