there is nothing different in the subs, they are the same.
the news one have a chrome dust cap, and the black coating,
and the jbl w12gti has the original grey frames with no chrome dust cap.
basically i have the 10wgti, and 1 is a older one and one is a newer one, they are the same subs and both work the same. its just a marketing tool to say yeah - look we have a new gti, when its just the same subs in a different color and dust cap.
they are great subs, and if your interested in getting one, its a great choice.