One bad thing with the A7 are the sensor reflections. Of you like to take photos with the sun or night lights you might want to go the D610 route. When I compared the A7 to my K5IIs at 6400 in raw it wasn't a huge difference. At normal viewing on a computer screen I don't think it's really noticable.
I do way too much pixel peeping..... Trying to get back to real perspectives. I rarely print high ISO pictures, but I just ordered some 8X10 and 8X12 prints that were taken at ISO 6400 on the A99... I'm looking forward to seeing how they came out. If they are solid, then I really can't imagine needed a higher ISO camera. If they are weak... not like I'm changing cameras any time soon, but then I'll greater appreciate needs for even higher ISO cameras.