The 670G is more than DOUBLE the size of the t.slim X2, but with the same capacity. What the hell Medtronic?

Medtronic 670G: 2.1 in x 3.78 in x 0.96 in = 7.62 in³

Tandem t.slim X2: 2.0 in x 3.13 in x 0.6 in = 3.76 in³

Is there any good explanation for why the 670G is such a monstrosity? Auto mode is eventually coming to the t.slim X2, so that's not a factor. Is Medtronic just cheap and using larger components to save money?