Well gents, it's here, and my first impressions are (nearly)100% positive. I have the D3 mounted to a Tamron 200-500, each with it's own Acratech Quick release plate. Center of gravity mounting is achieved in this instance by attaching the setup at the lens plate, but just to test the off-center load capability and performance I also tested the set-up with the camera (with lens attached) mounted to the head itself. Once the desired tension has been achieved movement in all planes is smooth and secure, staying put without further adjustment of either the tension or locking knobs. At every point in a near 180 degree range of the tilting plane the assembly held where positioned; a slight push or pull to any number of positions along this axis resulted in steadfast holding after re-positioning. Movement in the panning plane was flawless as well. Of course, you could lock the device in any position should you choose to do so. One nice feature of this head over others is the ability to rotate the angle of the top plate by 90 degrees, thus allowing for a vertical format pan - nice to have that feature for compositional flexibility.
Alas, my one criticism (with almost all gimbal heads) is the inability for lateral (left/right) tilting. To solve the problem of moving in that plane I simply mount the gimbal head (or the Acratech in this case) to a heavy duty ball head. One could achieve leveling by fussing with the leg extensions on the tripod, but I find the "ball head base" to be a more expedient and surefire solution. It would also be nice to have a universal quick release plate design rather than the camera-specific or lens-specific options provided (you'll need a camera plate for any set-up where the lens lacks a tripod-mounting collar, so you're in for the added cost of two plates anyway. And they screw in with a supplied allen wrench, making them essentially "permanently" attached). Apart from that, no further issues worth raising.
The unit is incredibly well built and beautifully engineered. They could easily charge more for it, so it's nice to see one company that does not gouge the consumer.
An impressive tool and a sound investment.
Cheers,
Robert / Seattle