Having actually taken a closer look at the hull numbers, assuming 6 phasers, 4 torpedo tubes, one thruster, two nacelles and a standard warp drive the Miranda should either be 230kt or 180kt depending on if it uses standard or heavy shields. 28 cost will buy 194kt of standard shielded hull or 142kt of heavy shielded hull.
This should give it either 46 or 45 shield and either 48 or 38 hull. If we do assume that it's slightly heavier than a canon Constitution, it would be 230kt which is also a Kea-sized heavy cruiser? I guess ships are getting bigger? It's also entirely more durable than a Kea and better armed to boot. How is this midweight?
Regardless, if it actually is the 230kt ship, we're a fair bit more durable with an extra 30 shield and an extra 10 hull and we'll hit harder with a similar weapons fit that all deals more damage, but we really do need to differentiate this by the modules. The Miranda will probably be refit with the same weapons as the Federation at some point (the same number too if we go with 6 phasers), so we're not going to hit harder for long. I still think it's probably worth spending extra to get full coverage, so we don't have literally the exact same weapons as a Miranda post-refit, but it probably doesn't matter that much.
That means our only real differentiation (aside from being 50% more durable) is our much-improved cruise speed and our extra 70kt of space, so we probably need to figure out something that involves a whole lot of flying all the time if we want to see a decent order quantity. If the Miranda is actually 230kt and carries a basic science lab, extra shuttles and cargo it'll probably have like 5 cargo modules, so that might make a dedicated cargo hauler unattractive. I'm not sure what else benefits so much from the max cruise, though. Emergency response or high-value cargo, maybe?
