6D might as well make Hakumen pick his non-existent nose. All depends on the active frames though, if it goes away immediately like 2D does, instead of sticking around 5D's, then yeah, next to, if not completely useless.
Saw an interesting strategy in the vids posted here. Going into OD right at the beginning to bump up a few stars to work with? Don't know if it's worth it or not, how long until your burst/OD comes back? Or is it dependent on a factor like, getting it back faster the more you take hits?