Well folks, I tried it and I am back to Mountain Lion.
I have a Early 2006 iMac, CPU upgraded to a Core 2 Duo, firmware updated to iMac 5,1 with 3 GB of RAM.
I used the SFOTT method and it worked. It installed but I could not get the sound to work, and there was no graphics acceleration. (No KEXTS for ATI Radeon X1600)
So if you have an iMac, don't install Mavericks quite yet until the Mavericks Post Factor is out. I know there were a lot of people asking this on the thread, so now you know.
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Thumbs up!
I am running the exact same setup. Thanks for the info and being willing to be the guinea pig on that!