I've had a couple tamahagane blades and don't expect them to be magically better. . . A yasha yukawa tamahagane knife had really really great steel but the grind was like a sword, so it was basically a deba, when it was supposed to be a yanagi.
I've had a tamahagane razor, iwasaki that cut hair super readily and more than any other razor but didn't shave with my preference. It wasnt as crisp as other good carbon steel kamisori that I've tried, that don't catch into hair quite as readily but go through it easier for me. I've also had another tamahagane kamisori, and 2 tamahagane Kanna. . . I have regular carbon steel knives whose steel I like more, so buy makers of you want, or steel I guess.
Takagi for example had thick edges but thin blade faces, and he made my favorite honyaki steel I've tried.
Anyhow, good tamahagane is supposed to sharpen like or easier than white steel. And to me, tamahagane feels different, almost plasticky or hammered (?) compared to white steel.