Don't forget, JR radios are positive expo to soften around center, opposite of Futaba (negative to soften center, as mentioned above).
Yeah, I forgot that once and nearly buried a brand new P-51 on its 2nd flight! The elevator was really sensitive on the maiden so I dialed in some expo. I put +60% instead of -60% expo on my 9c[X(]. I had the hardest time landing, must of went around 5 times!