Pretty interesting, some things though disturb me:
It has a pretty high drag factor, limiting the speed a lot. About half the value would still be huge and permit roughly to exceed the speed of sound at 10 km at full thrust, not 17 km.
The camera position would be better, if it would sit at the bridge and you could see the large spacecraft.
The hover engines are equally powerful as the main engines, but only the main engines are visible. Does not feel right.
Also the ground scenario is without landing gear (after loading the scenario).
What did not disturb me: Really nice model, has a distinct look, the texturing works and is not that big for the detail, it is a well optimized mesh for me. It flies pretty for its huge size, I might have expected it to be a tiny bit more agile, but then, it isn't flying like a carrying yak cow.
On a small note: Better leave the spacecraft3.dll out of your release and tell people to install this add-on first. saves a few KB in the ZIP and you don't overwrite an eventual bug fix of spacecraft3.dll with your add-ons version.