I've recently been using full calibration for my guide cam (QHY5 not Lodestar) and it does clean up the image displayed. But keep in mind that the displayed image is stretched for viewing, and that may be why you're seeing "interlacing" exaggerated. If you manually play with the screen stretch, usually by moving the right slider to the right more, you can see a cleaner image.
That could be why the image appears cleaner in PHD. The data should be the same, just displayed more stretched in Maxim. Maxim uses the raw data, not the stretched screen display.
I also usually always manually select my guidestar instead of letting Maxim choose it automatically. I like control.
