I figured that's how you'd feel about it Since I've taken steps into modeling I imagine I'd be the same way- especially with something unwrapped and textured!
Many of these points are on accuracy- the most glaring being the size of the deflector dish. I noticed how much 'forehead' room you had between the neck and the top of the deflector tunnel and saw that, well, it was more than what we see in the shots. The sensor on the underside of the saucer also had an extended 'notch' from the others, pointed aft? The NX in STIII had no such modification (you can see it in the scene of the ship just before Mister Scott leaves engineering). And while there's no good shot of it, the structure at the front end of the shuttlebay isn't cargo doors- it's some pod thing with lit windows. There's an image on Ex Astris with a specific closeup- visible only for a smidge when Enterprise is pulling into spacedock.
The other things are just minor texture things I guess. The shuttlebay can be fixed with re-texturing and lighting. But one of the prominent pieces of paint missing is a blue band running around the perimeter of the secondary hull. You have a trench there now, but it's distinctly a band. You're also missing the registries on the nacelle's back ends.
...Anyway, that's that. Your Excel is Excellent otherwise. I suppose I have a keen eye for these detail things because I'm thinking about setting out to make a high-poly high-detail accurate Miranda model, if I can actually get around to it. Unlike the Excel and Enterprise though, the Miranda/Reliant does not have a wealth of images about it charting every detail. In fact, I'd say out of the TOS federation movie models, the Reliant has the least amount of photographic references. There are AT LEAST two conflicting blueprints out there on the internet as well!
Except, none of this exists. You are making models based upon models. To be that technically fussy about conjectural ships based on studio models and fan speculation is just a bit of a reach.
I went through the ultra anal stage years ago making armor models, including casting my own "correct" parts, brass, etc, 200 dollars worth of reference books to work on a freeking 15 dollar model, and at the end of the day, about 3 people actually cared. And this was basing off actual, existing Armor, with plenty of actual references. This included, of course, finding new references on a completed model and trashing it over some idiotic scale measurement off by a minor amount.
It's not worth it, nor is it worth it to critique others work on minor details of nonexistant real ships. The original makers of the models had fun, that is what we should do as well. Minor inconsistancies abound in the movie versions. The overall look and feel is what matters.
And no matter what inaccuracies there may be, there is always the Paramount Explanation. "Ah.. Umm, Alternate Timeline, yaaa, that's the ticket"