When I first started sailing IOM's I found it very hard to be gentle steering the boat and one could see it zig zagging downwind especially in the vicinity of marks. I tried playing with the exponential setting which for a few months I adjusted the wrong way and could not understand why my steering was so violent. However once I got the setting right I found it did not really help and decided to work on finger dexterity instead. So I went back to standard settings without exp.
Recently I bought the Futaba T6K because it had a ratchet on the sheeting which can make upwind sheeting more precise and I felt it was more reliable product. See a previous post.
Reading the manual again the other day, I came across a note that said you could lengthen the control sticks which I have duly done. Making them longer gives me more control over fine steering the boat and I am still comfortable inside the waterproof cover. I have 4 more sets of races before the ranking event at Milton Keynes so I will see how it goes and whether it makes a difference. I believe it will.