First off, there is no such thing as "DBZGT"

Dragonball Z, or DBZ, is the middle, and longest in the three series of Dragonball.

Dragonball GT was a shorter series that came right after the end of Z.

Dragonball GT: Final Bout is the game you are referring to, and I have played it before. It kind of sucked because they tried to make the graphics too good, and didn't work on the gameplay too much.

That's why the new DB game for PS2 looks good, the system can handle the graphics.