Yep. I hate to break out the bad news but this is true. I am running OSX Snow Leopard and Kies is a damn hog. I kept wondering why the processor speed was going at full blast, making the fan on my MacBook spin non-stop. Turns out that Kies was doing something in the background and looping too. I have heard that Kies does similar stunts on Lion so please mindful of what you run it on.
On the iMac, Kies OSX can be a resource hog as often as it wants as the larger systems have the capacity to cool the processor down but on the Macbooks, you could well burn out the logic board.
One reason why it goes loopy is due to the OTA sync. The moment your phone connects to a WiFi network that your computer is on, it initiates the desktop program to run in the background. So Kies OSX will keep running at full speed at a alarming 107 percent…swallowing up all of the processor resources.
This is bad. And my advice to you is to watch this carefully should you ever install it on your Macbooks.