12-inch armwand on Graham Phantom II?

I recently picked up a Phantom II and I'm thinking of trying it with a 12-in. wand. Does anyone have experience with this arm as a 12-incher? Does the longer length improve or detract from its already excellent performance?
Indeed. Special order at $1,250, according to the distributor, MusicalSurroundings.
I must be blind but I see no mention of the 12" wand on the Musical Surroundings website. I do see mention of it by certain dealers but no separate sale details only complete arm price. Does this longer arm come with a bigger counterbalance weight or is one to use the standard stock weight? The SME V-12 and 312S come with a bigger weight to provide more appropriate counterbalance for the longer length arm.
Wrm57 please provide us with all the details you can.
It's not on the site. Sorry, I don't have many more details yet. My local dealer stopped in at Musical Surroundings yesterday at my request and inquired about availability. One week turnaround on special order, he was told. MS immediately sent an email to Bob Graham to find out about effective length and pivot to spindle distance. I'll ask about the larger weight, too, and let you know everything I find out.

I just asked my dealer about the counterweight. He'll check with MS but believes the stock weight is fine b/c the various arm lengths were designed to be plug and play except for mounting distance. I'll report when I get more info.