Thalassicus
Bytes and Nibblers
The outright bonuses (faster tech, cheaper units, cheaper upgrades) for the AI were all reduced in BTS. In addition, espionage was added and most AI's seem to devote 10% to that, further slowing their tech rate... just step up a level in difficulty if it seems too easy. I dropped to Monarch to try out all the new wonders and units in the game, and then went back to Emperor.
I'm finding it a little easier, but at the same time more realistic. The AI doesn't hide all it's workers when your army comes within 10 tiles. It prioritizes vulnerable cities with more units and walls/castle than distant ones. It builds stacks of naval forces and actually attacks, rather than defensively scattering 20 ships around each by their lonesome within their cultural borders to be walloped individually by your 1 stack. There's some marginal improvements, but like mentioned the straight cheat-bonuses have been lowered.
I'm finding it a little easier, but at the same time more realistic. The AI doesn't hide all it's workers when your army comes within 10 tiles. It prioritizes vulnerable cities with more units and walls/castle than distant ones. It builds stacks of naval forces and actually attacks, rather than defensively scattering 20 ships around each by their lonesome within their cultural borders to be walloped individually by your 1 stack. There's some marginal improvements, but like mentioned the straight cheat-bonuses have been lowered.