Effects of coagulants:

Coagulants differ in those effects to taste of Tofu and curding time. Any of coagulants works well in case temperature of soymilk is high.
Each of following coagulants has each feature. You could use just one of them for producing Tofu but by blending some of those you could produce Tofu with your special features.

Magnesium chloride (Nigari) :
Magnesium chloride is the main component of Nigari. Nigari is liquid produced by removing salt from seawater and it is rich in magnesium and calcium. Magnesium chloride easily dissolves in water and congeals soymilk much faster (fast-acting) so it requires some skills and techniques.
Especially it is very hard to produce watery pudding-like Silken Tofu, so that this coagulant suits for Firm Tofu (Momen Tofu). When Tofu is produced with this coagulant, it would be the sweetest in all 4 coagulants

Calcium chloride:
This coagulant resembles magnesium chloride in its feature, easy to dissolve in water and fast in curding time. When Tofu is produced with this coagulant, it would be less sweet in comparison with magnesium chloride but it has a virtue that water goes out easier than magnesium chloride. So this coagulant suits for Tofu Pouch because of such a virtue.

Calcium sulfate (Sumasi-ko):
Calcium sulfate is hard to dissolve in water, congeals soymilk slower (slow-acting), which is easy to handle, so that this coagulant has a feature that Tofu tends to be watery, smooth on the tongue and bouncy.
But this coagulant cannot produce Tofu, not as one with magnesium chloride in the sweetness.

GDL is produced by fermentation-method taking starch as materials.
Other coagulants congeal soymilk by ionic bond but this coagulant uses oxidative coagulation. GDL congeals soymilk much slower therefore even temperature of soymilk is around 90℃, this coagulant facilitates congealing soymilk as pudding-like, which leads that Tofu becomes smooth on the tongue and watery.
But as time goes by, taste becomes sourer then taste of Tofu will be different from the one before.