Like most hits, the tracks just mixed themselves because the arrangement and sounds were so complimentary, but what stood out to me most was the groove. Every single track just felt so good.
I remember soloing the hi-hat track (which was surprisingly isolated) and marveling how just the hat alone sounded like a hit. No other instruments, no bleed from other tracks, just pure hi-hat with a groove that had hit written all over it. I don't know that's ever happened to me before or since, at least in regards to a hi-hat track.
Which also plays into the theme of my last post. Today we strive for recording and musical perfection at the expense of the groove, but if a track doesn't feel good, nothing else matters.