I just got a Weber Genesis 310 after coming from a cheaper Char Broil infrared that had a trough over the burners and I'd throw some wood chips right on it. It added a little flavor but they didn't last long. I mostly want something for this grill to add a little smoke when I cook something quick like salmon or chicken, but also something that will last long like if I'm doing ribs or a whole chicken. What works better: the tubes or tray? I am at sea level and since I have read that altitude matters. Also, when using this while doing indirect heat, do you put the smoker box on the side over the burner that is lit or the other side?