GI lighting is very important to me. I hate not being able to see the ball on any game. I never really appreciated how fun JD was until I bought a cheap one and put 7 spot lights in it. It is a completely different game now. I think Stern has done a good job on their last few titles out of the box, especially Star Trek Pro that is nearly perfect GI wise IMO. I have played 3 different WoZs so far and the ONLY one I really enjoyed playing was one that had upgraded GI so I could actually see the ball most of the time. I had dismissed it as a dull game before that and could never seem to get anything going. Once I played on the bright one, it was like playing a completely different game.
I agree with NEO as well, I don't think any designer intentionally designs a game to be dark, at least not in the middle of the playfield.
I think I am more interested in seeing the color palette they use with the mulitcolor LED's in this game. WoZ really lent itself to the full spectrum color explosion that RGB LEDs can provide, but it seems like TH will need a more muted tone to look 'right'. That is why I am not a fan of the color and cool white LED's in LotR. Warm whites just look better in that game IMO.