Yes, 30% expo is -30 on a futaba, +30 on a JR... HOWEVER!, everyone is different so you'll have to feel things out... I don't like any expo on my airplanes... I use just a SMIDGE of expo (like -5 or -10) on my helis nitro helis... For ALL my micros though, including the T-rex, I found the BEST for me was actually a fair amount of POSITIVE expo... (on futaba)... This makes it "more" sensitive around mid-stick, rather than less.... What I found, was that with the micros, you CONSTANTLY have to give small corrections to keep it in a solid stable hover... With no expo, or negative expo, you where moving the sticks all over the place and it was almost hard to keep up with (especially other micros aside from the t-rex)... So, with POSTIVE expo, the "Corrections" can be input VERY fast and with very small movements... This makes it easy for me to keep that thing in a rock solid hover with no problems at all... Then when your doing turns, or FF, etc... as soon as you leave the "center" stick portion it smooths out and makes things nice and easy....