Vince;
You're on the right track. Rarely will a heli fly perfectly straight in all attitudes. I routinely use pitch to cyclic mixing on all my helis to trim them for hover and full power flight both upright and inverted. Generally the amount of mixing needed is only 5-10%, but it really helps to trim the thing for hands off hovering and flight in all orientations. It also helps to get the rolls smoothed out. I trim mine exactly the way Mike Goza explained in his article, and have for a number of years. Hope this helps. Steve.