If you ask me, the Imladris warp shuttle and the Matson-class starships are nice. However, I wouldn't count on 'em being UEP/TE starships without having a Federation counterpart of their own (one that looks more "innocent" than a UEP/TE take on the design).
"Why?", you might ask. Well...
If you ask me, the totally-different Terran Empire/UEP starships and WIPs may look nice, but they would never ever exist in the Mirror Universe still, in my opinion. If you want a true Mirror Universe with the Empire existing in the 24th century, events and ships must be similar, albeit not identical. Perhaps basically the same, yet with differences that make it dark and evil, much like Diane Duane's I.S.S. Ent-D description or Atolm's "re-imagined" I.S.S. Enterprise. But I'm probably repeating what I had said before in the thread.
Whilst it's my opinion of an idealistic "Mirror Universe" to mirror the Trek universe in a dark way in the 23rd and 24th cenuries, I'm sure not many would agree with that, nor would many limit themselves to the Physics dealing loss/addition of mass and energy (as it can't be created or destroyed) like few had. It wouldn't be interesting for space battles between good and evil Terrans. *shrug* So if we go by that, some of the designs recently displayed/linked here are alright.
Quoted from
this thread. I just didn't feel like repeating myself. However, to address the other designs... I'm unhappy with the other designs however as they seem more like butchered designs ("butchered" isn't the appropriate term, but I don't want to be vulgar unnecessarily) of different class of starships. A Constitution-class with an Excelsior-class secondary hull turned upside down and stuck on a pylon running down to the secondary hull of a Constitution-class? There's almost no similarities (aside from basic design lineage) between each class of starship...
And the attempts I see here of schematics and models to blend the Sovereign-class look kind-of ludicrous in the same basic reason the Glamdring is... Okay, to be fair, the Excalibur in the picture one isn't bad as I exaggerate, but it doesn't look that well as a kitbash. Neither does the Quasar with its upside-down Sovereign-class secondary hull (without the warp nacelles and pylons being upside down).
The Asteroth reminds me of other attempts to "Dreadnought-ize" the Excelsior-class, and although it's not terrible, I wouldn't count on this design to be more than a fanboy's dream as well. The same goes for the I.S.S. Tiberius, but set at the TOS-era. Four warp nacelles with an oddly-placed secondary hull with two "necks" that only attaches to weapons, and a dozen other weapons? Even for the UEP/TE it's a fanboy ship.
I doubt most any of 'em would ever find a home in the UEP/TE as it wouldn't mirror designs from "our" universe. Otherwise, what's the point in calling such an alternate universe
the "Mirror Universe"? The concept is two universes. Our own, and a
parallel universe. Very similar in appearence. Similar in each ship design, yet darker and deadier. Similar in crews, yet the same; darker and deadlier. More "unpredictable" for people like us who aren't savage.
But nevertheless, some designs here are very good, like the two I pointed out before at the beginning of the message.
(Edit: I think I just repeated myself... Oh well.)