The great thing about Sim City 4 is the increased depth in building facilities of all sorts and the new rush hour U-Drive it missions.
The Regions are a good feature because it lets you connect your cities. However an established region can take many, many hours to create.
There is a big lag in graphics when you zoom in. It takes twenty or so seconds for everything to settle and the pixels to dissapear. Even so the graphics are mediocre.
Another fault is that your cities can't get very large. The largest I have got in a regular sized map is 100,000 people. In a large map I was able to amass a reasonable 350,000. In other city builders (ex. City Life) your cities can grow over 1,000,000 just like real megacities.
The Rewards Concept in the game is an old feature from Sim City 3000 (i haven't play it) and I think it is nice and broad, in other words there are many rewards to be unlocked.
This is the best city builder I have ever played!!