Do you like rolling? Do you enjoy rolling, fast? If you answered yes to either of these then this may be your best pick for bearings.
These aren't rated at an abec but handle very similarly to abec 9, they're made with extreme precision resulting in ultra-low torque for some of the most ultra-efficient energy transfer and high speeds. Despite this precision, these are still tough cookies so don't be afraid to put them anywhere and everywhere!
Go Project make these with a single nylon shield which looks great first of all, but holds up better than steel shielding. Go get 'em!