Looks really good to me
Are you modelling all the panels by hand ? They look really good. The only part that bugs me is probably the "bridge" on top - its edges seem a but too sharp when compared to the rest of the ship. Other than that just keep adding smaller details because everything seems to be working now. Oh and if you didn't do them yet, model the engines
I can't see the back so I don't know if they are there.