Obvious bugs are obvious, but I'm really digging some of the visual concepts here.  As others have said, it is rather a departure from other ships.  At the beginning of the thread, I was thinking that this might be a civilian ship (thinking supertanker or possibly a deep space explorer).  But now it is looking armed to the teeth!  It presents a very wide target cross-section from pretty much any direction, but I get a sense of mass and strength from it as if to say, "So what?"  Might be a good fit for a particularly arrogant faction.  Someone with access to lots of hardware and resources, but not necessarily a pure military background.  Perhaps this was originally a civilian ship but it has been re-purposed for a more bellicose role? 
The turbine-looking things on the top rear are also intriguing.  What are they?