Upload & Sell: Off
I know this is bad form for this forum, but, Canon has made your camera- they call it the 5D III .
There isn't a very significant difference between a 5DM3 and a D610. If the 5DM3 is someone's dream camera, the D610 should fit the bill unless you have very specific needs (in fact it's better in some very key areas). Slight edge to the AF on the 5DM3 (I honestly couldn't tell a difference when I tried both under any normal circumstances), better video, and 1/8000 shutter. Beyond that there is very little differentiating them, and some much more important advantages to the D610 (much better sensor, ~$1300 less, spot metering at any focus point, crop mode, etc.) Build quality is essentially the same (metal frame with alloy pieces, both bodies have the lens mount screwed into plastic and are fully weather sealed). I shot with one for a while and went back to my D600. The ergonomic debate is entirely subjective, but I do prefer larger cameras regardless (5D3/D800 sized). No way in hell is that camera worth $3500 (to me) when the D610 is $2000. Apart from the megapixels, the 5DM3 has barely caught up to the 7-year-old D700.
That is why the D810 has me so excited. You get a true pro build (1pc magnesium w/lens mount attached to metal), D4S AF (hopefully), the best sensor out there, and at least 5 FPS. You also get an amazing 15MP DX camera when used in crop mode, or a 6+ FPS 25MP camera in 1.2 crop. Jury is still out on the FPS specs though, but if they can squeeze 5-6 out of it, I think that will please a lot of people. If you get all that for $3500-$3700 I fell like it will be a steal, considering the 5DM3 sold like hotcakes at $3500 for less camera. I realize not everyone wants 36MP though, so I would like to see a "pro" body build around the 24MP sensor as well with a little more speed, but I'm not holding my breath on that one - the D810 will have to do .