General Fusion was interesting until they repeatedly failed to meet their own timelines. Commonwealth Fusion Systems is meeting their own timelines thus far as their design is very run of the mill, other than the magnet technology, which they've already demonstrated.
They also changed their design to use a rod down the middle (because the previous design didn't work for three different reasons.) Now they are exposing that rod to orders of magnitude higher neutron fluence than the wall of a typical DT reactor design, as well as subjecting it to forces from magnetic fields up to 100 T. I am not optimistic this will work.
