Yeah, in my opinion, it's more difficult to design Federation ships than any other Scifi craft because the elements are so pre-defined. Even with shows like Star Wars, you can get away with a variety of different and unusual designs and they'll just fit in the universe. You can in Star Trek but only with unestablished alien designs. If it's something 'known' i.e. a Fed or Klingon or Romulan ship, than it has a lot of 'design baggage' that goes with it and has to look a certain way. That's why I especially loved the Klingon designs of the Vor'cha and Negh'Var classes. They had such an awesome continuity and yet were a definate evolution from one another. I think that's why I was never much of a fan of the new movie Enterprise. She has all the elements there but you can tell they just hadn't read the manual! LOL!