Most people probably don't like the Gemini given the cost and what you get in it as a combat ship, but after some thinking I believe that it can be made viable. Not the best, no, but viable enough to be an additional option when you're in the early and mid-game and are struggling to get ships that can more quickly deal with the enemy with lower risks of death.
Now, why do I think the Gemini can be worthwhile? 4 things: Reserve Deployment, Medium Missile slot, EMP, and Medium Ballistic slots.
First, RD: RD's benefits are quite obvious to most people, but to optimize it you have to play to its strengths: utilize wings and fighters with longer times to replenish both individual ships and whole wings, and wings that strongly benefit from the number of additional craft. The magic numbers are 2 and 4, which give you 1 and 2 (respectively) additional fighters for the best bang for your buck.
Medium Missile Slot: Both the Annihilator Pod and Pilum LRM have good damage, and tons of ammo to fire on potentially many many different targets. The only problem is that they're either too slow, weak or dumbfire. And that's where EMP comes in.
EMP: I really like fighters with EMP for two reasons. EMP typically costs a lot of flux, so offloading it onto your fighters is free flux dissipation for you, and fighters will naturally flank, so killing ships engines is a breeze, making them sitting ducks for your various missiles.
Medium Ballistic Slots: Medium Ballistics gives you access to excellent PD and more easily accessible long ranged kinetic weapons to kill your opponents shields. Gemini has comparitively more limited flux dissipation considering it's weapon mounts, so you can really only afford a single kinetic weapon. Ideally a Heavy Needler, but Heavy Autocannon, Arbalest, Light Needler or Railgun are fine, too. As for the other slot, I like a Flak Cannon for the PD, range and efficiency. If a frigate gets within range, it's highly efficient as a whole against the combination of defenses. Dual Flak is good too. And you can eventually drop an HVD or two on it to keep it effective in mid-game.
Anyway, the strategy here is essentially just disable engines, overwhelm shields, missiles go kaboom, and to do that you're going to need either a Thunder or Claw wing. Thunder benefits from getting a 50% increase in the number of fighters in the wing from RD and circumventing the long 15sec base replacement time (2x15sec=30sec). Claw benefits from a lesser increase of fighters, but can replace a larger build time equivalent of fighters (5x8=40sec). I prefer the Thunder because they're much faster, provide greater shield pressure, the rockets are nice distractions for the PD, they themselves are helpful as PD, and their massive engagement range also pretty much guarantees you can catch a ship trying to flee. Claws are great totally disabling ships, however, so they go well with Pilums if you can't get your hands on Anni Pods.
Devils Advocate: You can do a similar build with the other two carrier destroyers. Condor is slightly cheaper, but doesn't open up the option for Medium Ballistic weapons and has drastically worse flux stats. It also doesn't have Reserve Deployment. While that's easily offset by having two flight decks, it also means you'll need to procure an additional fighter lpc, which can create some problems. Getting your hands on two Thunder lpcs is going to be difficult, and mixing Thunders with another type will have compatibility problems; your Thunder fighters will always get to the target first, which may result in their premature death, meaning you now have wait to for them to rebuild to get that EMP on the ship engines. If your other wing is a Claw, what's the point of having the Thunders if they're going to have trouble with replenishment and getting their EMP off? Might aswell opt for something more effective against shields....but then you lose the incredible speed and engagement range to chase flee'ers.
Drover only suffers from being stuck with small slots, but that's sort of made up by the higher flux stats, additional missile slots, and additional fight deck. You would go with 4x Swarmer instead of 1x Anni Pod. If I had a choice, I'd pick the Drover as it has a higher ceiling of capability and viability further into the campaign. It is, however, 33% more expensive and requires more slots filled with potentially rarer stuff.
And finally, the cargo space is also really nice at the beginning of the game. Many people underestimate the usefulness of gratuitous amounts of cargo space, especially at the beginning of the game, even if you're going full bounty-hunter. Think of how often you have to keep going back and forth to sell stuff. That ends up turning into a lot of wasted monthly supply and wasted time while bounties tick away. It also limits how many supplies people are willing to stock up on. One of the things that helps me tremendously with early game is hunting for cheap supplies and getting as many as I can afford and fit into my fleet. And because supplies cost so damn much in the majority of stations, it's very simple to liquidate my stash (for a significant profit) when I need to buy something.
Again. Not saying Gemini is exceptionally good. Just saying it's viable early to mid game until you replace it with more efficient carriers, freighters, and platforms for long-range kinetics.
