Root works, but keep in mind that the same bugs with GB27 still exist. Specifically, when I rooted with GB27, I lost my paid app and I could not reinstall it. I tries to install and then gives me error, "Couldn't install on USB storage or SD card." Tried a few things but could not fix it.... so I had to flash back to stock GB28.
Update: Didn't realize it before but after flashing back to stock GB28, I still have root. yay!