This paper studies distribution channel structure strategies (to centralize or decentralize) for two competing supply chains that sell substitutable products with price and lead-time sensitive demand. We find that centralization (decentralization) associates with itself a price (lead- time) advantage and a lead-time (price) disadvantage. As a result, price substitution and lead-time substitution have different impact on the equilibrium channel structure. Specifically, price substitution favors decentralization whereas lead-time substitution tends to result in centralization. Our results show that the equilibrium channel structure may critically depend on the game type (Bertrand vs. Cournot) and the profit criterion (manufacturer profit vs. channel profit). In the Cournot model, centralization for both chains (CC) is always the only Nash equilibrium. In the Bertrand model, CC is still the only Nash equilibrium for the manufacturer profit criterion. On the channel profit criterion, however, it is the relative intensity of price and lead-time substitution that determines the equilibrium channel structure.