I haven't had a problem... but I can see how you might:
- The sediment tip is bigger than most racking canes.
- The inner tube must be push down as far as possible - it needs to be below the water line.
- The inner tube does not push *all* the way in.
Even with these limitations, I've never had a problem getting all of the beer out. I try to leave a very thin layer on top of the trub after fermenting... that will get a little yeast in, but not enough to make a difference (and usually just enough if bottle conditioning).