Hey Jay, not to drift too far off thread... that Highlite's a great bag. I have a WM Antelope that's been with me for ages; last year I was going to send it in for an overfill because the loft was horrid. WM asked if I had cleaned it; I had. They suggested I clean it a couple more times. So I took it to the laundromat, washed it, left it in the machine and ran another wash cycle, took it out, centrifuged, then many hours on low in a dryer. Came out as good as new! Basically, I had just used the bag too much with too few washings and my body oils had built up on the down too much. Any chance you might just need to wash it a couple times in succession? Might be worth a shot.
And, um, in the spirit of the thread, converting something like that Highlite would make for a great quilt! (Especially if you cut a little further down...)