I'm 6'0" with long legs. It's very hard for me to do ATF squts without losing balance or bending over too far. So when I do ATF squats, I go much lighter than in doing the "thigh-parallel-to-floor" squat. In other words, I can use much more weight going with the latter. However, I wouldn't waste my time doing any squat less than at least parallel.
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Backstage, '75 Olympia:
Serge Nubret, "I look like I can take you."
Arnold, "Keep looking."