I prefer medium games.

Just don't want to spend days playing a very large game.

I play mostly Medium with some Large maps. Medium games for me is neither too short or too long and have a decent number of opponents. Large tends to take too long for my taste but I like having more special areas to explore.

Well, I'd say you should optimize for normal sized maps, not small maps though, if I wanted to play small maps with some crazy action I'd play StarCraft. I personally play on the largest possible, as I enjoy a long game with lots of (potential)chaos going on, though I do not load out a lot the factions, as I prefer to go a ways without meeting anyone. The moment you run into another faction, it is instantly a pissing contest and you either have to pay tribute or go to war. And I could rant for days about how I'd prefer the power rating system actually be used and diplomacy etc, etc.. Anywho, off topic for a moment.. The new animations are sexy as hell. I'm in love with Tidal Wave and Blizzard.

I usually play on the largest size maps with  large numbers of ai opponents, but to speed the development of the ai I would suggest medium size as small map games usually end fairly quickly and do not get to develop all the techs.

harpo

Since there are three sizes now, and most agree on medium size being a good compromise, I would say optimize it for medium.  If later on we have big 64-bit maps than that would be the time to make changes for the 64-bit version.

I always play large maps with max AI.  I am using Ecomental Xlarge with 9 opponents.

I am playing Medium right now as I learn the game.  But I tested a couple of times and it looks like my computer will handle Large and that will become my default Setting. 

It's pointless optimising until the resource generation bugs are worked out.  You'll be sitting there wondering how the AI sovereign is so godlike and then you'll look at their mana level - yeah wow, three hundred million?  No wonder they're so buff, they've been popping Destiny's Gift/Insight every turn, the cheating gits.

I like medium or large maps.  I have never played a small or tiny map, ever, other than the premades.

I want the biggest damn map possible.

I play Tiny or Small near exclusively. I want a fast game. Obviously you shouldn't optimise AI for just that though.

XXL with ecomental - lush and ecology

What's the drawbacks to the AI on being on a too large or too small map?

I'm assuming too large= vuln to turtling and too small= vuln to rushing.

What might help is if the AI could study a player's tendency and adjust its odds of action based on that. (but not perfectly as that would be too predictable)

I am wondering why you are optimizing for a specific size?

If you are doing automated game running, to see how the AI deals, I think I would do repeated runs with either random or continuously varying settings.

Optimizing suggests "over training".

Still, if you must, I would go for the game defaults.  (But, personally, I play with the huge map mod, and wish the map could get bigger than that, but I can already see my machine struggling...)

Edit: note also that I turn off the victory conditions which allow a single player to win without involving anyone else (spell of making and master quest), and these also reflect potential optimization issues (and so do all of the other options for map building).

The bigger, the better.

I'm not sure what optimization is meant to be with the map size...as far as I know, the bigger map, the most optimization would requiere....

But after some large, extralarge and huge maps, now I'm playing medium maps with many AIs, to encourage land fighting and earlier battles...

It would seem to make sense to optimize for the default value, since that's what is recommended. And since it's mid-way, it should scale down or up. Maybe have different algorithms based on the map size?

Medium...it's just right for me...since if large map cost me many more hours and lag, slow game...

I play on Large, but Medium would be a sensible place for optimization.

If you could add two new AI traits - Claustrophobic and Agoraphobic - then that might make things interesting when you have lots of opponents squished into a smaller map, or very few opponents on a big map.