You indicated that the curved track traveler effects trim and you're right but it shouldn't. The traveler only adjust the angle of attack and trim is not effected as it moves but what happens is when the traveler car is moved off center and if the mainsheet is not adjuster the car is traveling downhill and acting like a boom vang and accordingly changing twist and draft position.
When I purchased my C30 the traveler was the first thing I looked at. The second was the pin type jib cars. Anyway, trying to save a few bucks, I had Garhauaer build me the double block system your friend has. I knew the first time with the new setup that it was a mistake and I should have bitten the bullet and purchased the straight track, which I did. I should have "cried once" instead of twice. I didn't make that mistake with the jib cars and purchased the Garhauer adjustable system.
