TLDR: A great city building game that could've been the best for years to come. There are too many issues though.
I still rate it 3rd for me after Simcity 3000 and 2000.
Beware of the compatability issues, performance issues, bugs and illogical things (the save menu WTF).
The city building is solid and all the info you need is available. Sometimes the city's management information is a bit hard to find, but it's there. You don't have to lay down power lines or water pipes, which I didn't like at first, but got used to. The roads can be curved in any way you want which is really cool.
The game is easy at first and the tutorials are good (not voiced though), but there is a big difficulty jump when your basic utility facilities aren't enough for your city anymore. The city will start to demand more electricity, fuel, water and waste disposal very suddenly. Also when you start building high density stuff the demands go up quite a lot.
The game also seems laid back and fun instead of taking itself super seriously. Just like Simcity 3000 did (And Simcity 4 didn't). It doesn't mean it makes the game any worse as a simulator, but more fun to play.
Graphics look really nice and are freely rotatable and zoomable 3D. You can tilt the view upwards/downwards with only 2 presets though.
I can't really get why some people complain about the graphics.
You can zoom in to see the details, which I didn't really care at first, but I found it's really cool to see your cities from the street level in the "postcard" camera mode.
Sounds are what you'd expect in a city builder and music suits the game nicely. The intro song does play a bit too much though.
I have not run in to any compatability issues with Win 7 64bit, but there are many people reporting them on the forums.
And the to the negatives:
The game runs fine when building a small city, but when the city size reaches 500k people or so it brings any computer down to below 10FPS in some situations (like making bus lines or zooming way out).
It runs only in single threaded mode, but also must be optimized poorly. Some tweaks to the game files help, but not enough to make building big cities fun.
There are some bugs like sometimes the trading does give or take more money than it should, some special building names or descriptions not showing up properly and one or two sounds not playing properly (police station is one).
And then there are these logical issues. When you click a diskette image in the menu that is labeled "Save" and in the following interface click a save thumbnail, it LOADS the save instead of saving (there is a confirmation dialog, but it's too easy to just click ok). Also it overwrites the autosave instantly at that moment.
There are more of these issues, but they're just annoyances, not wasting hours of city building!