From my own experience, endurance and strength come from either faster reps, or more weighted reps. Essentially, if the power wattage output of your body is high, you'll benefit immensely.
Ever wonder why speed skaters have some of the most muscular legs around? Its simply the number of unencumbered 'squats' they continue to do over long periods of time while practising.
Sure you can lose weight quickly with HIT and HIIT (High Intensity Interval Training) but we need a lot more study to confirm that they are genuinely 'better for health'. At the moment, they're just a variation...like variations :)