Just to be the fly in the ointment I have to say the nicest Witches Nebula shot I have ever seen was done with a modified Nikon D800 and an AP130. Its a 2 image mosaic.
So there is life in modded DSLRs. The latest models are more sensitive than the previous generation. The Sony Nex 6 or Fuji XE1 also would make a very good astrocamera- APSc sized high quality Sony Exmor sensors.
I have just ordered a Nex 6 and intend to modify it. I'll be posting results with it soon. Although I will mainly be using it for nightscapes I do intend to use it for the odd deep sky - just to see what its capable of and how far these cameras have come.
http://www3.asiaa.sinica.edu.tw/~whw..._Head_2013.htm
Greg.