Ok, you had one before, so you understand how they should fly by comparing the current to the previous one. Is any thing different between the two? Engine? Prop? Where you put gear? Did you change throws or expo on the radio setup?

The reason to check the CG again is becasue of the relation between CG, incidence and thrust. There isn't much point in chasing thrust and incidence if your CG isn't in a reasonable location. If the CG is close (probably +/- 1/4" on that plane), then move on to the next check, incidence. Then the flight tests. Cheers.