In this paper, we have experimentally compared synchronized versus asynchronous all-optical deflection networks. We have compared four routing modes: synchronous mode, partially synchronous mode, and asynchronous mode with fixed or bound packet sizes. Our experiments mainly show that the natural decrease of the performances of the asynchronous mode, compared to the synchronous mode, can be balanced in a significant way by the use of a sophisticated routing algorithm. Moreover, we have also shown that asynchronous routing is not very sensitive to bursty traffic. These results, and the fact that asynchronous networks are easier to design, and cheaper to build than synchronous networks, show the practical interest of asynchronous deflection routing.