I don't really see why classical Golden Ages are that great.
One of them only applies to religion, and another requires good faith generation. Free Inquiry.... how many districts will you have to take advantage of that? The only consistent one is +1 culture per district.
With a Dark Age, you can take Twilight Valor and use it to fight or even take Monasticism. Loyalty from dead civs don't matter. I mean, I suppose if you had the oppurtunity for a Golden Age, go for it, but as the other thread kinda shows to me, it seems to come down to "get really lucky" and isn't really a decision to begin with. I suppose it coming down actually to normal vs dark age, being the actual choice that matters.
The difference isn't even close if you have a Classical Golden Age with say Harvest and Monumentality.
Chop your way into free builders, settlers, trade routes and most likely some other goodies.
Just the fact that your builders can move faster and improve on the same turn is kinda a big deal.
Not to mention when you do warmonger with that Classical Golden Age you slice through the enemy like butter.
Combine the two Golden Ages together and it gets even better compared to a Dark into a Heroic or Normal into a Golden Age.
Again, the point is that back to back Golden Ages are far superior compared to throwing yourself into a Dark Age so you can go Heroic.
I haven't figured out how to get that Classical Golden Age with ease but when I do it is a major difference compared to a Dark or Normal Age.
I tend to constantly fall short at 22 or 23 era points instead of the required 24.
This doesn't mean smarter players aren't able to do it every single time on Pangaea Maps.
The way I understand it is they do struggle on Continent Map types and other Maps for that matter.
However I find any map other than Pangaea guarantees a win.
Of course how fast you win will separate the better players.
The best games or fastest win times always have back to back Golden Ages.
I have never read of anyone winning some super fast game with a Classical Dark Age.
Of course I could be wrong.
Edit: I just played a game testing if I can get harvest or not and I was Cyrus.
I ended up getting harvest on turn 25 and decided to play it out a bit.
I only had two cities but I did have double horses.
Not sure if I need them with Persia though.
Anyways I didn't do so well but I did get Classical and Medieval Golden Ages.
The game just got out of hand. I had 18 cities by turn 100 with two settlers getting ready to settle.
I knocked out two Civs heading to a third.
Constantly Faith Buying Settlers and Builders.
I couldn't even keep up with the snowball that happens from that Classical Golden Age.
Transition into another Golden Age for a back to back and it gets pretty silly.
The AI got to a point where they were pulling 30 SPT as the top leader.
I was at something like 150 SPT.
I wasn't even doing it very good and it was OP
Better players would of finished with the Domination Victory around 110 or so maybe sooner.
I tend to do poorly not working on enough Army or splitting them up.
To make matters worse I was wiping them off the map so that takes more time.
I had 32 cities on turn 125 and just saved the game because I lost interest.
My point is that Classical Golden Age with Harvest is far superior to throwing yourself into a Dark Age.