The 'gifting' of features which seemed to begin in the late 60s as James pointed out was a strange departure for Sears, at least as I see it. The 70 series had always been year to year stable, features wise, and they had most of what buyers wanted. To get the full-frills however, one needed to go to the 800 or the Lady Ks. By 1974, this full-feature lineup scheme was nutty...my mother's second washer was a 1974 entry-level 60-series, however it had infinite water level, the five full temp combinations, two speeds, a self cleaning filter, softener and bleach dispensers, and Pre-wash and soak cycles, and the off-balance switch. About the only thing Kenmore could do to spruce up that model any further was to add a detergent dispenser and a better agitator.
I guess Sears came to their senses in a year or so in the marketing department, as by the 1976 debut of the black panel "wet look" machines, the entry level 60-series had lowered itself to having one-speed, no pre-anything cycles, no dispensers, no off-balance buzzer, and not even a delicate cycle, and it was back to a manual clean filter (the fun part of that model). The next year or two the 60 got a little more stuff on it, but the lineup seemed to return to the early to mid 60s mentality and packaging of features, which remained for the rest of the belt-drive production and for a lot of the DDs well into the 90s.