I'm not sure what to make of it yet myself, might need to play a few more games to properly assess it. But it is having a dramatic change in my gameplay strategy as I adjust to it. I've become almost paranoid now as my young cities are quite vulnerable. Until I'm confident they can adequately defend themselves, I keep an army near by (generally my Sovergein early game).
This changed allot, and I'm thinking it might be restraining the city spam we are use too previously. In my current game I defienetly can't spam cities, no way. The risk of loosing them is too great, and my economy is not developed enough to have multiple armies to guarantee their safety. Add to this that city razing pretty much ruins the area, I have to really be vigilant. That city is gone forever, so much is at stake, and this does add a new kind of tension that I'll admit I kinda like.
Curious to know how the AI is dealing with it? Guess I'll find out soon enough.