Instant vs. Sorcery

do you think it's better to have an instant version of a sorcery in Big Deck, even if it's more expensive?

e.g. Fault Line rather than Earthquake

It depends on a lot of things. In my aggro big deck, id rather have the sorcery just because its cheaper and includes less red. You have to look at the overall costs of the cards and the mana requirements of the cards and see if one fits better than another. Its too hard to decide on a rule for everything.

That one damage (or whatever) may or may not turn the tides of battle. I think having it at Instant speed in the right situation is good compared to having to wait.

Say my opponent is at 10 life and I can EQ next turn for 10 or Fault Line for 9. Before it comes back to me they may go down to less then 10 at which point I can take them out fast. If not, I still can during my next turn.

~Zuty