In my humble opinion... I agree with some of the guys here, in some points.
I agree with Drew when he said "It really depends on the subject" and what my friend Harry said is correct, "Look at the real thing and try to duplicate it."
And I agree with Matt's simple two rules: "Enjoy yourself" Don't forget, this is a hobby and it should be fun not work, and "Be cool to others". I agree with that. Not everyone has the same skills as others. Some builders could build amazing works of arts and others may have to work really hard at their builds. Me personally, I don't mind a bit of helpful criticism. But I'm not a Master Builder. Like a very good friend of mine that did AWESOME Paint jobs on his models told me, keep it fun.
I consider myself a Moderate builder. Not an expert... yet. But I have lots more to learn. That's what I find really enjoyable and fun about this hobby. I've learned so much from my fellow builders and try to apply what they showed me to my builds. Every build I create is a little better then the last. In truth, we all learn from one another but find different ways to apply the skill.
Me, I try to build my models as accurate (as the model kit allows) and as detailed to the real thing as possible. I do allot of research on the subject to apply to my models. Even with that, sometimes I can't help myself to do some custom details to them. Again, it's all for the fun of the hobby. I made one promise to myself: Once the hobby is no longer fun, that's the day I will stop building.
So to answer your question of Shiny or too Shiny... I would have to go with my friend told me. Build it whatever way makes you happy... Super Shiny or Flat gloss.
Happy Modeling.
The Cat-Man =^.^=