I have ambivalent feelings about the readiness system so far.
I like how it forces you to rest your soldiers between missions and expand your roster as a result.
I am mostly indifferent about the in-mission effects. Mostly it feels like added complexity without an increase in gameplay value.
The stamina meter, though simplistic, always seemed adequate at simulating physical exertion in a long battle. Easy to understand, easy to manage, very punishing if you run out at the wrong time.
About the morale effect, I must confess I haven't even noticed that one until I read about it here. I guess I must have been lucky. Bughunting never took me long enough for my soldiers to freak out.
Still, I don't like the idea of punishing the player this way. Punishing campers I understand, but it isn't always up to the player how long a mission lasts. Searching for the last enemies after a successful fight can't be that stressful, at least not any more stressful than the preceding combat.
I also can't think of any scenario, where soldiers would be so mentally depleted after a long battle, that they start losing their minds and possibly shooting at their comrades. That's a bit extreme.
What
would make sense, is if soldiers low on readiness took higher morale damage from the usual sources. That could also apply to stun.
The first item is to agree on what a game turn is. Based on numerous posts, it appears each turn is equivalent to 1 to 2 minutes of real life. This means a base defense or Cydonia, with 100 turns can be between around 1.5 to 3 hours of fight.
Strange, to me a turn seems very short. Based on the actions a soldier can perform with full TUs, like shooting a bunch of rounds on full-auto (+time for aiming) or running a short distance, I was thinking mere seconds. No more than 30 seconds. Very short turns would also explain rookies' inaccurate firing, since they don't really have much time to take aim in a frantic combat situation. It would also explain how they run out of stamina so fast.
All of this is assuming, that a lot of the actions, which happen within a turn, are happening at the same time or at least overlapping.