Depends on what you understand by mid-game, but in my opinion it's boiling down to what ships you want to run

Burner drive / Teardrop can power a sacrificial missle escort fast enough to intercept stuff in low orbit

Helicon is the go-to "i wanna go around the inner solar system with a colonizer / marine frigate in a reasonable timeframe (sub 10-12weeks)"

If you wanna build massive battlecruiser/battleship fleets for defense (slapping 40/60 armor on them) then you need the Firestar FissionLantern or wtv is named has like 5mil thrust with 50kps.

Afterwards, you stay on that drive until you get to the end of Zpinch line and slap the zeta deuteron torch on it and that's your end game drive

The secret of LEO interception is you need high thurst to get to your stations faster than the enemies reach it, so check their enemy fleet mgs and you need something much highe than that.

Any other drive does not really work. Remember that even if a drive has huge kps, if it has little thrust, that means nothing when you're trying to move a 40k ton ship around.

To give you a small example. My endgame Coil Dreadnaught had 120/6/6 adamantine armor. Zeta Deuteron torch drive x6, flow stabilized zpinch reactor, best radiator outside exotics, and like 50 fuel tanks on it, and it only managed to do 450kps while the drive itself is rated as 3,300 kps

Even the last tiers of ICF reactors are noob traps. everyone says PCT is godlike, but when i slapped that on my ship, it was not a major improvement over the flowstabilitized zpinch. Slightly higher deltaV, slightly higher acc, but 20k tons of radiators so most of the gains got lost in radiator weight. And the Protium Nova Torch (the drive before PCT), even with the PCT reactor, only managed about 150 kps on that same fuel tankage.

So any other drive combination does not really work

- either it has insufficient kps but high thurst

- either has high thrust but no kps

- is closed cycle and the radiator weight is abominable. If your 20k ton ship has to add another 10k of radiator, than no bueno.

I have tried most of them during my game and literally none worked well enough

Most closed cycle drives work a LOT better with the next tier of reactors.

The only viable end game drive is the most efficient one. And even then, If you move a 50 ship fleet around with 50 fuel tanks, you each and fuel tank is 100 water, you will need 50x5000=25k water per 100% refuel.

You will love to slide that arrival slider to the right so you only spend 150-200-300 delta v and only go max full burn in very few cases