Isn't a game where your hard efforts to achieve a tech dominance is nevertheless only going to keep you just ahead of your competitors more fun than one where as soon as you get ahead, you gain steam while your opponents slow down? Pretty soon you're going after your enemies with tanks and they've got archers and longbowmen. I'm a bit tired of that scenario but at the same time if I start off at a high enough game difficulty level, they sprint out of the gate and make it next to impossible to share in getting some of the first-to tech bonuses like religions.
This leads to either a fight the opponent with greatly inferior armies but superior strategy OR a fight the opponent without any challenge at all kind of scenario.
I'd love to see a game where it tends to go down the middle of the road. Tech diffusion can help there. And it works both ways... if they're ahead of you its going to help you to catch up too.
It's terrible game design to have opponents who fall behind have no possibility of catching up. It tends to be that way in Civ, like in Risk. The one who gains an edge has an increasingly less likely chance of losing it so no 'comeback' is really possible by any player that's fallen behind. It should be the opposite. That's exactly what tech diffusion helps to achieve. AND its rational. AND its an option so if you prefer to play a game that has no challenge once you've gotten ahead, go for it.
You bring up alot of points. Yes, it is tiresome, the lack of challenge at that point. But you know what? That's when you win the game, and move up a difficulty level. That's the very nature of difficulty levels.
But you know, I played on noble on BTS for the longest time, even though I would always get bored around the renaissance era because I was do far ahead. Why? Because I hated the fact that in order for the AI to be a challenge, I had to give them unfair advantages. While the principle was my reason for not playing higher levels, I can see your exasperation at the old "slowly slowly work your way up, never getting any of the cool stuff in the beginning." Hell, look at any deity LP. That's how they ALWAYS go. The person is last, or very near to last in points, then through superior strategy (usually military), they break through and dominate.
Yes, the AI having its massive benefits on deity is what causes this scenario, this...artificial difficulty. You would give it more? The original devs of Civ IV already failed in having implemented tech welfare and other handicaps as a "difficulty". It would be a shame to see this mod continue that trend.
By the way, have you tried flexible difficulty? It seems like it would address that ultimatum at the beginning of your post.
As for its realistic nature, see my above post.
As for it being an option, rest assured I am very, very aware of this. I am also aware that if this tech diffusion becomes the way you modded think you've "balanced" the game, then any future cries from me to address the challenge of the game WITHOUT the terrible principle of "whoever is behind gets tech welfare", be it to the AI, or heaven forbid, me, will be met with a dismissive, "Oh, stop complaining and just check tech diffusion."
It is the fact that focusing on tech diffusion as the means to "balance" the game (unfair welfare is never balance), prevents you all from focusing on true remedies.
You guy's holy grail would be to increase the AI's capabilities so that noble is the perfect difficulty in terms of challenge. Not too much, not too little, where the vast majority of players can start a game with no way of knowing who will come to win, and keep that suspense throughout the game, WITHOUT any artificial difficulty.
Real difficulty, not artificial, please.