Pirl, I had no idea that Hakone grass could grow so quickly! I am zone 6a (just re-zoned from 5b). My hakonechloa is a solid performer, but definitely not a fast spreader.
I team it with a pale yellow blooming daylily & makes a nice show.
I think it adds the appearance of motion to the garden because the leaves bend over in the same direction & sway a bit as well. I also think of Hakonechloa macra aureola (& Hakonechloa 'All Gold') as being one of my 'bright lights' in the garden. In shady areas they both seem to glow a bit.