As for the article, really interesting. Sounds like proof of the power of SimCity's engine. Would be more interesting to see him fix his issue.
Absolutely buying this on release day - gorgeous game and IMO a large improvement over previous installments. The only things that bother me is the limited size of the map (unsure if it's a beta thing or not) - if I can't build a megacity I'm going to be sorely disappointed.
Traffic model, economic model, new zoning model, and new utilities model are all IMO simplifications that make the game more fun, but does not remove depth. For those who haven't followed the game: power, sewage, and water no longer require power lines/pipes/etc, and travel along roads. They propagate along roads outwards from their generation source (water towers, power plants, sewage plants, etc) until their capacity is reached. There's a great animated overlay view that lets you monitor the state of each of these pretty easily.
The biggest pleasant surprise was how well it ran. I pushed all settings up to max and it didn't even flinch. SimCity 4 in contrast got insanely slow when your city became even slightly large - even on today's hardware.
The ability to monitor cashflow is also a welcome change. Instead of having to dive into your balance sheet to figure out your fiscal position it now shows a very clear flow rate (negative or positive) next to your balance.
The other major drawback to Sim City 4 is that there is a bug which prevents rich ($$$) Sims from working in the High Tech industry. The only way to fix this is to use a 3rd party mod.
The short version is, your sims must find a reasonable commute from home to work, otherwise your economy stagnants and unemployment runs rampant. SC4's pathfinding heuristic disallows a sim from going backwards to go forwards.
This creates many transportation deadzones and a lot of unintuitive bottlenecks. You will literally see sims live directly next to a subway station that takes them directly to work, but they will drive instead.
There is a mod to fix this, but the performance impact is expectedly awful.
It's not as bad as you described it. It's even worse.
The hack the creators of SC4 used to get around the problem of traveling the same path twice in one trip is responsible for a large waste of CPU cycles. Essentially, the hack allows the Sim to "forget" how he got to a certain location and start a new trip to the final destination. The downside is that this is that all of the information from the previous leg of the trip is lost, and the algorithm must run again. There isn't a 1:1 ratio between the amount of citizens and CPU cycles wasted, because as your city grows the path each citizen must take becomes more complex and consumes more cycles.
You can read more about it here, at a third party fan site. [1]
[1] http://sc4devotion.com/forums/index.php?PHPSESSID=fcff28ec82...