According to traffic statistics via PokerScout: Not so great. In fact, traffic for the days since the boycott started is essentially unchanged week over week, and Revolution has managed to hold on to their spot as the largest US-facing online poker room by real-money traffic.
A quick survey of the Twitter accounts of Lock pros provided in the boycott thread failed to turn up any tweets or conversations regarding the boycott. The last tweet from long-time Lock pro Eric “Rizen” Lynch on July 8th suggested nothing but business as usual:
get your piece of 100k guaranteed on Lock Poker in 40 minutes!!