Any word on whether the game has elevated beyond the state of terrible?
Why would I play this an not SC4 instead?
It has not.
The problem with that is that the game was designed horribly to begin with. It is baked into the game mechanics now. They cannot "fix" things without changing the way the game fundamentally plays, which means that nearly all the existing cities wouldn't work and/or would collapse under the sudden implementation of some realism.
So basically, the game is broken, and that's just the game. Maybe they'll fix it in SC6. If you want a decent city simulator, SimCity 4 is still the best.
-SC