<<The grip is thinner but ok, not as great as the D300>>
Reminds me of the D7000 grip when compared to the MB-D10 on the D300/D700
<<The D800 is far closer to the D300(s) in usage.>>
As was the D700 to the D300.
<<Btw, I thought the balance of the D600, even with the kit lens, wasn't too good.>>
Found that too on the MB-D11 D7000 grip. Obviously no magnesium alloy content, only good quality plastic.
My concern would be that it's launch price was particularly high for an entry level FX, however even now the UK price has dropped as much as £350 ($525 approx.) on Amazon already. No other retailers have really discounted. I guess it will fall to a much lower level, so why such a discount merely a week after launch!
The descriptions I am hearing make it in my mind a FX version of the D7000 in terms of ergonomics, functionality and build quality. I also wouldn't like to loose the AF-ON button and it annoys me that the D7000 hasn't one either.
If the price settles to about 60% of launch it will be a good FX entry level or second camera body buy I think.