all i know is that if u can get an authentic persian or middle eastern bong, u will be happy... they have some wicked designs, although i have seen some contemporary ones in the states as well


but a good bong to me in technicality is a bong with longer trunk, u can get bigger hits, and also how deep the intake pipe hits the water... the deeper the smoother the hits

also it should be somewhat of the right weight, depending on type of ur consumption, some people wanna move it around then u want a smaller one as big ones turn out too heavy for regular move arounds especially after u get blown :P