Turning off UAC means that anything you run while signed on to the Administrator account will have full administrative rights. That's an invitation to infection by viruses and other malware...
Yup, but I guess Number13 (wow, lucky 13 in that name - omen?) doesn't care. Hence, my "use at your own risk" statement.
I myself have gotten use to UAC and find it not as intrusive and annoying as it was under Vista.