I think it just depends on what you want out of your knife. Both are high end and aren’t necessarily meant to be thrown in a toolbox and used at a construction site. The edge maintenance of the Shiro will be much easier since it’s a standard V-grind and not the convex edge of the Rockstead. Not that convex is hard to maintain, but I believe that Rockstead recommends only to strop on bare denim as maintenance and sharpening needs to be done by sending it back to Japan. To the resident experts: If I’m wrong on that feel free to correct me. Neither knife is fragile, but I can only assume with the super high HRC on the Rockstead that you inherently lose toughness. Not that you could pry a car door open with a Shiro either but I’d rather have slightly more toughness at the expense of edge retention. That’s just me though, YMMV.
If your work is more of the “suit and tie” type and you really only plan on opening Amazon packages, cutting tape, and slicing paper then I’d go for a Rockstead. If you want a knife that’s easier to maintain at home that has good steel at a more standard HRC, then go for the Shiro.
One last thing. When it comes to warranty both are going to have to be shipped overseas to their respective countries and it could be a while before you get it back with everything going on right now so be sure to take that into account.