ATI drivers + Xorg 6.8

I'd really like to be able to use the fancy new composite stuff available as of xorg-6.8.0. Unfortunately, it slows my computer down way too much for me to leave it on permanently. I'm thinking that the reason for this is that I'm using the xorg radeon driver instead of ATI's binary drivers. If I try to install ati-drivers (Gentoo ebuild) it wants to downgrade to xorg-6.7.0, which defeats the purpose of the change to ati-drivers. Are the ATI drivers completely incompatible with Xorg 6.8 and am I just SOL here or have people had success convincing them to work together?
Thanks in advance...