Slight size difference is consistent with a slight increase in power. With the same Imp (assuming Indonesia vs. Vietnam), they likely use the exact same cells, but the higher Vmp of the 215W indicates they have a few more cells in series for higher voltage/power.
These must be used on an MPPT controller to capture the additional 15W. If you use them on a PWM controller, they will perform identically.
7% more power for 4% more cost? Assuming the slight size difference isn't an issue, 215W is my choice.