M-Audio's firewire series devices are in the same boat. They don't crash the mac but the m-audio control panel in non-functional.
It amazes me how companies can wait until folks start screaming to get up to date. It seems this could have easily been avoided with a little forethought.
It just leaves a sour taste having to do without a critical piece of gear while waiting for software updates that should have been developed months before. I did abandon M-audio for a Behringer x32 and this experience with line 6 has me looking at alternatives as well. I hate to even think about it because I have been using pods for many years and have been very happy. I have a Variax as well and the integration of the two is perfect for my needs. This is not a show stopper for me at the moment because I do not use my X3 as an audio interface but I do hope the fix is imminent for the times that I need Gearbox.