That's actually my favorite method! Since you end up having a fairly accurate plot of the target's course after all the doodling needed for speed calculations, I use the same plot to get the AOB.
Of course, that means that I either hit exactly where I want or I just accumulate errors from the first step and end up shooting down an unsuspecting seagull
If we had accurate data for the length of each ship, the Aspect Ratio method would maybe be preferable. I have tried using miniatures from Axis & Allies: War at Sea and a protractor. They work "ok". It's not really accurate but you feel like a million dollars estimating AOB on your computer table with scale models
