The one thing nice about uniflow, is that you can make it either uniflow or standard vent by just changing which one you plug. All of my tanks are uniflow, but I do run some of them as standard vent. I generally try it both ways and see which works best for the set up I have. My McCoy 40's like standard vent tanks, so I plug the uniflow, and leave the standard vent open. As a rule the standard vent tanks will speed up some towards the end of the flight, and uniflow's do not. But I sometimes get a better stunt run on standard vent, and sometimes on uniflow. That is why it is best to try it both ways. I have also found that when running uniflow, I have to have the needle richer on the ground, as it will lean out more in the air, where with standard vent, it will richen a little in the air.