That's certainly interesting, I didn't know Cura had that issue. I can't say I've noticed that issue with slic3r. I have it set to start each layer in a random point. Though, I might not be understanding the struggle you are describing or could also be experiencing it without realizing it.

Are there any dealbreakers keeping you from using slic3r? I hadn't heard of simplify3d, what features does it have that you're interested in?