Good points all. But i agree that the mirror universe ships would not be identicle as different situations would create a different outcome. aAship of war would not look like a ship of peace(unless intentinally...lol ).
The Enterprise can just as much be a ship of war as it can be a ship of peace. It's who uses 'em and how. Lets say Khan was successful in taking the Enterprise in Space Seed. He will use it to colonize and conquer, no? The Enterprise turned into Khan's ship of war. It's certainly powerful-enough. The purpose of "Mirror, Mirror" was for the writers to make an alternate universe almost exactly like our own, but subtle changes to make things darker (or at least the story concept was to be like this. It's how I percieve it at least). Had the budget problem been nonexistant I'm sure the Enterprise model would at least have been painted darker or something, something to indicate that it's a warship in the Mirror Universe. Whilst I would agree with you guys, it would only be up to a point.
By how you go, I'm fairly certain you would mean ships of war would be different entirely by configuration, the Empire would have more class of ships or different from Federation. I would judge such universe as an alternate universe similar to that of the Mirror Universe's, much like how'd I would judge DS9's Mirror Universe as just an alternate universe similar to that of the Mirror Universe's.
I was fascinated by the storyline of a parallel universe that seems to go just like our own, but with subtle changes that would make humans much-more a warlike race Q saw our species as in "Encounter at Farpoint" (TNG). By how I go, I'm fairly certain the Terran Empire would have ships of war, but because it's a universe paralell to our own, how I get it would that their class of ships would be basically like our own, but only basically. They'd probably be a bit more artistic in their design to express their war-like attitudes, such as darker hulls, ships that look like animals stalking on prey.
I kept referencing to the decade-old Next-Gen novel called "
Dark Mirror", a novel that focuses the Terran Empire (In the novel, it's called the United
Empire of Planets, not just Terran Empire) and what they've been doing. Now that they are aware of us, and that the Mirror Spock's predictions of the Empire are true, they've been plotting to take over the Federation in a unique way. The I.S.S. Enterprise-D is a warship, and similar-looking to our own Galaxy-class U.S.S. Enterprise-D. However, as stated before, the ship's hul color is darker, the saucer is curved more to a frown-like shape, the nacelles lowered and swept forward a bit, the secondary hull a bit bigger. And internally, the I.S.S. Enterprise-D (weapons-wise) is superior to that of our own Enterprise, with faster warp speeds (and able to maintain it longer), more weapons (even the standard Phaser and Photons are more-powerful), etc. (The story itself is set at the fourth season of TNG)
So while I agree with you guys (after some clarification problems fixed on my part), I only agree to a point. I feel the DS9 stories, Shatner's novels, and the general idea of Terran Empire ships (and stories revolving around 'em) makes the Mirror Universe only less up to its nickname. Although I would agree that it wouldn't be so mirror-like for long (when refering to Mirror Spock's prediction), my impression of the Mirror Universe beyond 2268 would be like how the crew of the Enterprise-D would discover a hundred years later.