Liquid Antimatter sees some use against False Gods (although admittedly it's win % isn't very high).
I would doubt that it does much better against AI5, the only reason it works is because of specific False God decks where the knowledge of what to do, or how many card they have is key (even if the player knows nothing, the deck was designed to beat the ones it can beat). There you would have to make do with what you get while it would keep piling on different (useless and useful) creatures.
However, in a standard False God Killing deck (meaning 1-5 auto quits, you try most of them depending on your hand and ect), I would expect survivability to be corrolated directly, especially in rainbows which usually have cards to adapt to different situations, and you'll find a lot of these situations in AI5 (This is most true for rainbow decks)
Some, like RolHope which basically depend on the opponent lacking certain things (In this case, Mass CC, a way to bypass shields and sometimes quanta denial) will be much less predictable with AI5s, since their cards are pretty much random.
So, my final answer (this is all based on guesswork, assumption and basic knowledge of the game) is that it is epecially true for rainbow decks, or decks that want to be able to beat most/all of the False Gods. Otherwise, it is a good indication of how long it takes you to get set up and deal the 200 damage, but with the randomness and weaknesses of specific decks, you can't always trust your results.
