Far more accomplished musicians than me have played and reviewed this cymbal over the past few years - all I can do is agree that this is a magnificent piece of bronze that inspires with its shimmering response.
Not sure how this compares to the original Giant Beats of the 70s (as I don't have one to compare) but can say it is somewhat similar to a 20" black label 2002 Medium. I understand the black labels were thinner than the red label models, as the GBs are thinner/lighter than the 2002s, so perhaps makes sense.
I'd say this GB crashes with more shimmer and wobble, and is slightly darker with less high end cut, but a similar fundamental tone. Lovely stick definition and body with pleasing wash when used as a ride, as I do in lower volume settings (i.e. not with the hard rock band :-)
Maybe worth noting that this is actually the 'multi-functional' cymbal, not designated specifically as a crash, and certainly not the thin crash as shown in the image in the item description. There is a 'thin crash' that is a separate beast - probably lovely too.