D200 Guy seeks input from D800 Owners...

I want to go FX soon. The question is: D600 or D800.

But wait, not so fast. DX lenses look ugly through the D600 finder. I heard somewhere that the D800 finder masks down to DX when using those lenses. True or False?

Also, I know that the D800 can shoot lower mp images. But I don't know whether the D800 is just throwing away pixels in those modes, or making good use of all pixels through some kind of averaging or binning. Could someone please tell me? I wouldn't feel at all bad shooting lower-mp-but-lower-noise images while saving up for my 100 TB supercomputer.

I also see the 4:5 aspect ratio choices as a huge advantage. (3:2 is nasty to my eye, and losing the 3:2 "shoulders" would be a perfect way to lose some unwanted mp.) Can anyone comment on whether 4:5 works well? And does it mask the finder in some way?

Lastly, I wasn't too happy with the recently published D600 "teardown." It's construction seems more unserviceable/disposable than I'd like. I'd like to believe that the D800 is more serviceable, not just heavier. Does anyone know? Has anyone seen a D800 "teardown?"

Other D800 pluses include more/better controls, USB3, and maybe a few more. So the D800 is definitely in the hunt.

Yes, I'm aware of the whole left-AF issue, and Nikon's poor response. But I don't know whether there is any hard evidence that this problem is resolved in current production. Do any of you know? (Guessing won't help me.)