There is the TDM Mod which 'tweaks' the AI for a better opponent. IMO it is a must-have.
Some mods have the TDM optomized AI's with it.
Devnull Mod for sure. Perhaps P&N Mod and Proportions as well.
The above mods (and many more) have changed the gameplay greatly.
There is also a Mod that claims to be tweaked to get the most out of an AI. (I remember that it has built-in advantages for the AI. Chooseable at game setup.)
Hope this helps and welcome back!
