Last Janurary I had much better flight options when I didn't log in at all. I was able to get a HNL-MSP return on the 330 (nonstop) at low but when I logged in (as a PM), it was high and the only low option was OGG-LAX-MSP.

Just the opposite when I booked MSP-BKK for this Janurary. Nothing at low unless I logged in and checked the box.

Just my experience.