Im pretty sure not much has changed since i wrote this:
http://www.subsim.com/radioroom/showthread.php?t=104377
I know it says , "GWX's AI" but it's also really an explanation on how the AI works in SH3. I dont expect SH4 will be much different excepting with the addition of thermal layers.
As to adjusting the AI (something which i tend to do), im not gonna bother until i get more ingame experience with it to see if its too good or too dumb. I suspect it is probably too dumb, but im giving it a chance first.