I don't have a lot of experiance with the giant beats other than i played a couple in a store up in cleveland and i really liked the 24". I was very impressed with the shape and weight range(even though i don't know it it was nice and thin on the edges). It had a nice dark wash with good stick and strong bell.
I do, however, own a 24" zildjian in the 3200g weight that is very nice sounding and has lots of volume. I think the giant beat actually sounded better but i didn't get to do a side by side comparison. My vintage(early 60's) zildjian was about $150 cheaper than a new GB.
I have a friend with a 24" zildjian in the 2800g range that is just remarkable and sounds better than both of the other cymbals. Same stamp as mine.
I also owned at one time a medium late 70's 24 and sold it because the lighter 24 mentioned above just had more character. The medium, around 4200g, was nice but pretty much one dimentional.
What does all that mean? Not sure, pick the one you like best and fits the style of music/songs you plan on using it for.
Good luck, Gary.