I've heard tell of some people who managed to get 600k or so in SC5, but yes, it is crap. Highly visual and oooh shiny crap, but crap.
For those unaware, they finally came out with the offline version back in March, but I was so disgusted with the initial online only launch that I didn't even know this until a few weeks ago. I bought it, and am highly, highly disappointed. A HUGE step backward from Simcity4 in almost every area.
The city sizes are tiny. Basically, you can get a perhaps 10 by 10 city blocks in the city. This is probably about 5% of the size in a large city in SC4. It is unrealistic that a city of 10 by 10 blocks would sprout populations of huge skyscrapers and boast populations of over 200k. Unless it were a city within a sprawling metropolis, but that is not what SC5 is. You have huge empty regions with absolutely nothing between anywhere from 3 to 8 or so cities that are limited in size and have incredibly dense population.
Maxis says that the reason for this is that they thought peoples computers wouldn't be able to handle larger sized cities. Well, tough titty if they have to upgrade their computer once a decade. My three year old computer handles SC5 without a hiccup even with cities over 200k in size. Perhaps if people are having framerate issues, they should (gasp!) back off the sliders? Frankly, I think the Maxis response is a lie to cover the fact that online probably can't handle the large city sizes, and they are too proud to admit that online is a complete and utter fail and waste for a game like Simcity.