HI
I have a couple of suggestions.
I have found on my S006 that adding a little boom sticking out the front with a weight on it really improved forward speed a lot.
I can even fly it in a very light breeze now.
Here's a picture of the mod.
I used a piece of plastic shrink tube with a .45 cal ball in the end.
It is fastened to the bottom of the heli with black electrical tape.
I would also suggest that you might tryaffixinga light weight tube of some sort across the landing skids so that it sticks out on both sides to keep the heli from flipping over sideways.
Mike