I had to read this a couple times to make sure i got it. Thanks for that. As far as i understand it at least orbits and courses are much easier with chemical fuel because its point and thrust and all over in a matter of a couple hours. Your fuel is mostly expended and you are on the correct track with very small adjustments possibly required. An ion drive while slow is an exponential curve because its speeding up on top of the speed it already has. So instead of going from 0, to 1, to 2, to 3, to 4, to 5 it would go from 0, to 1, to 2, to 4, to 16, to 256. If i am understanding correctly this would far outsrip a point and thrust craft quickly. A probe to mars takes 9 months during the transfer window but i have heard estimates of 3 months for an ion drive craft