I've gotten everything working perfectly with my router and Mach3 *except* incremental jogging. Normal continuous jogging is perfect, but when I switch to incremental it moves incredibly slow. Like 10 seconds to move 1mm kind of slow. I adjusted everything I felt comfortable adjusting to no avail. What should I look at to fix this? I ran a fairly complex bit of gcode this afternoon and it performed perfectly, so the problem seems to exist only in the incremental jogging somewhere.

Incremental jog uses the feedrate. Use MDI to enter F10 or other rate first.