[NFP] Upgrading from Renaissance war. Do you go to refining or flight?

[OnThePath]

Going for oil units has the advantage beefier Combat Strength units, but is totally reliant on actually having access to oil.

But in a recent game I went for flight, as observation balloons are guaranteed to be available. They're not as sexy as artillery and tanks, but being able to out range an AI that's generally passive seems to work fine. On top of that you're on the way to roll for aluminium for arguably the best units in the game.

 

[Oberinspektor Derrick]

Flight without a doubt for me.
Balloons are very good in helping take down cities, as otherwise the siege units get blown up once they're in range of the city.
If you get unlucky, that by itself can stop a successful push while you wait another 20-30 turns to build and send new siege units to the front (worst case, if you can't buy them or have cities near the front).
You are also closer to Advanced Flight, and bombers are imo broken against the AI since they seem to never build any proper AA and the bombers themselves just level cities like nothing.
Usually for me, a domination game starts with some quick conquering in the Ancient/Classical era, followed by a very slow advance in the Medieval/Renaissance era (the AI has walls and your siege weapons are bad), before things speed up to ridiculous levels once you get Ballons and especially Bombers.

 

[CoconutTank]

My dom experiences are usually in line with with Oberinspektor Derrick's. If done right, I'll have eliminated my neighbors and taken my landmass very early in the game, then there'll be mostly down time till Observation Balloons and air units. However, it seems like Aluminum tends to be more scarce than Oil, but that may just be more incentive to reveal Aluminum as soon as possible in order to find out where to get it.

 

[hhhhhh]

Naval or Coastal warfare - go Refining. Otherwise Flight.

It seems like you are talking about beelining, since Refining is a modern tech, not an industrial one. Don't forget that industrial era cavalries (both light and heavy) are powerful.

 

[Bibor]

Observation baloons are the fastest way for keeping renaissance units relevant and is also great for tight upgrade budgets (both gold and oil)