PaulP,
the replies will be interesting.
i use blended (i rarely make it now, getting mine from home bargains as separate garlic and ginger paste) - quite a shock to me and my beliefs. the fresh is best though.
for madras i feel you have to add some fine chopped as an extra ingredient.
i don't hardly fry the paste or fine chopped - i actually add it while the oil heats up and then cook for 15 secs tops - just till i get that whiff. i feel it cooks enough through the rest of the frying.
the "zaal" garlic is a completely different entity which is needed for "garlic" dishes.