immortals are great if he got more marauders than marines(or tanks^^), else they become a bit obsolete, as marines effectively counter them and their hardened shield.
it's not too uncommon to see a terran not massing any tanks, just mmm and ghost/viking depending on what i do. tanks are only really good in a timing push, when you have little battles throughout they get kinda bad, cost/return is very low.
you could see in this game that i was annoyed by the drop play, game was over after 15min tbh. need to split my units better, blink stalkers are great for that - put them on the top of the high-ground of my initial bse, then blink them west to get into my main army if he decides to fight with his entire army.
the days of mass colossi are over, they get obliterated pretty badly by a dozen of vikings or just stimmed mm. i make mostly 3 to 5, after that i don't mass them, need the supply elsewhere. sometimes i hesitate massing them again after they get crushed and get HT/archon instead, or if the time is right, getting acrriers on the field
