Played with the 320X again this morning.
This time I had about 8g of lead under the grip + the overgrip, bringing the total to about 13 or 14g of additional weight (over stock form) in the handle.
Groundstrokes felt nice. My backhand felt great with this racquet. I don't know what it is, but my backhand is definitely very solid with this racquet.
I did feel that I lacked a little stability though, so I'm considering adding a little more weight.
I'm considering 10 and 2, but I'm also considering adding weight to the throat as well, just to bring the static weight up a bit and get more plow through.
As for my shoulder. It hurts about as much as it ever has. But the jury is still out on whether or not that is the racquet's fault.
It's been a long time since my shoulder has hurt this much, but there have been occasions when it hurt like this playing with my Fischers too. So I'm not quite ready to blame in on the racquet.
Bummer though, b/c it's difficult to demo the thing when I have so much shoulder pain hindering my serve and forehand.