At the moment, I just installed SC4 on my macbook since I haven't the room on the HDD to install bootcamp, windows and SC4. It's definitely not as good, whether the UB Patch will make it any different (whenever they release it), im not sure. i hope it'll be faster since it won't be translating through rosetta. but i'm planning on buying a bigger HDD sometime soon so I can then bootcamp etc, this is if the patch isn't released in the next 2 months anyway.
I have a macbook 1.83ghz, 512MB ram, so it isn't the most ideal machine to be running SimCity 4 on, however with more Ram and the UB Patch - i'm sure it'll be nicer. it's okay to run now just a big laggy in some parts.