Before ya'll start bashing the cygnos chip remember that it's currently the most stable way to reboot into a patched kernel.
I have two Zephyrs laying around, one with a cygnosv2 + freeBOOT 0.2 and the other with XBR 3b for Zephyr.
The XBR console supports unsigned stuff in many ways yes but it's not as stable as the freeBOOT 0.2 console.
For example I can turn the console off and on without having to wait between each power cycle with the cygnosv2, it will always boot!
If I turn the XBR console off, I'll have to wait for at least a minute before turning it on in order to get it to boot.
If I don't wait the jtag hack will fail and it'll display E79 and erase all my settings (which sucks since I heavily adjust everything from the video reference levels to auto-signin for my profile).