Say, I have used several different materials to change stuffing in my 510 cart. Polyfill, Fluval, and blue foam. The blue foam seems to go bad quick so I have been using the Fluval mostly. I guess my question is how long do you make the stuffing? I find if I bottom it out in the cart that I lose a lot of draw on the inhale. If I leave a bit of space between the stuffing and the floor of the cart that I get much better draw. Is this true with you? Thanks Ed