I ordered a G13 today to compliment my rev 1 G15. I may experiment with with the MWII software for the USB Xkeys and IS. Without the direct binding capability of IS, the Xkey USB is not very useful for me anymore. Should the ergonomics of the G13 agree with me, I may dump both Xkeys and only use the Logitech products for direct binding.
I'll wait for at least 3-4 weeks before I try to sell the Xkeys to give this issue time to shake out.