I have a Fluval 407 with a spray bar but in the end I found I prefer the duck bill. I have the main current flowing over some plants on the surface and the duck bill's force is reduced, but not entirely. The duck bill provides some variation in the current strength throughout the tank and I found my fish will ride various currents to get to different areas of the tank. The spray bar moved the water OK but there were no "interesting" areas that the fish utilized. I have angels no tetras, barbs, or shrimp, but I would think that the shrimp might find some currents pleasant. I don't know much about shrimp but the cherry shrimp I had seemed to like the areas of the tank with higher currents. To re-iterate the spray bar really reduced the currents in my tank.