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?
Is the 12-in. wand for the Phantom available?
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.

And what about the offset angle at the magneglide system? The offset angle at the bearings matches the cartridge offset angle, approximately 23 degrees, so when changing azimuth would not affect the VTA. Since the offset angle for 9" is different from a 12" I would assume the manufacturer would change to a smaller offset angle too. And that would require re-machining the entire bearing housing. Or do they leave the offset angle the same as before?

Very insightful question from Hiho. The inaccuracy resulting from adjusting azimuth would be slight (varying with the cartridge). It might not outweigh the reduced tracking angle distortion from a longer arm and reduced offset angle of the cartridge.

But it will be there...
I just learned from my dealer, who got it from Garth at MS, that the P-to-S distance is 292 mm for the 12-in. wand and the counterweight is the same. The range of cartridges shrinks from 4-18 grams to 4-16.

Apparently, Bob Graham is on vacation until June 9, at which time Garth will ask him for a cheat-sheet with comparative data for all armwands.
Would love to see the cheat sheet if it comes available. I run a Phantom Mk ii with a 10" arm wand on a TNT Mk IV.