One thing I'd like to add that may not seem obvious is that casting any pump or creature saving spells now open you up for a 2 for 1 from an opponent removal. With the old damage on stack rules, if you don't need the extra power from your pump spell, you would wait until the damage is on the stack before cast your protection/pump spells knowing that even if the opponent casts a removal then, you'd still kill the enemy critter with your damage, thus maintaining card parity. Now, you're forced to cast the spell early, risking a 2 for 1 every time. This may not seem to be as big a deal in constructed, but limited is all about these tricky combat plays.
Toughness pumping spells may save your entire team, or it may just cause a blowout. I don't know if this makes pumps worse, but it certainly makes instant speed removals much more valuable.
Toughness pumping spells may save your entire team, or it may just cause a blowout. I don't know if this makes pumps worse, but it certainly makes instant speed removals much more valuable.