I wouldn't count a duo Connie as a much greater force. It's far larger and has a lot of things that can go wrong. If something catches fire or power routers blow then one of those two will have to be running around to do damage control. It's large enough that a dedicated engineer should be required during combat.
The Redeemer is small in comparison. The turret gunner may need to get out for fires, but they should be contained easily.
Ideally, both would be fully crewed, but if you only had 2 people, the Connie will be the more powerful ship (when used against larger targets, not fighters). The pilot controls the main weapons, missiles, etc. With only 2 S4 weapons and a small number of missiles for the Redeemer, it‘s has a lot less firepower when the 2nd person is busy outside a turret. The ‘deemer also bigger than before, so it will still be a big target. I think it will end up being bigger than the vanguard.
That said, the redeemer will be a heck of a ground support ship with 4xS5 guns on turrets, much better than a Connie can. If it has the people to do it, the ‘deemer will be able to put a heck of a lot of sustained metal or energy on a target while the pilot circles (not hovers) from a decent range. It can then land and still be able to support ground operations.
As for fires, I plan on going into combat with the ship under vacuum conditions (If allowed and the crew has enough time). No O2, no fire
I also believe that when it goes flight ready, it will REALLY jump up in price...maybe even up to 350 USD, and a slight possibility of even higher, so those thinking about getting it when flight ready might consider getting one sooner.
i am not knocking the Redeemer, just saying you will need at least 3 crew to take advantage of a lot of the firepower it has.