Enter the Zercher Squat:
If you can deal with the elbow discomfort (varies from person to person, can be alleviated with padding, supposedly you get used to it), it offers these distinct advantages over the barbell squat:
(1) Less spinal compression since weight is not on shoulders.
(2) With weight low and in front, you can maintain a more upright posture.
(3) You can squat lower, really down into the hole.
It's what I would call a self-limiting exercise. You're constrained by a number of factors including how much you can deadlift, how much pressure your elbows can endure and how heavy you can go and still rise from a rock-bottom, dead-stop position.
I consider self-limiting a good thing. It means that in theory, at least, it is harder to hurt yourself.