I've noticed this too, AI builds a lot of starbases, but doesn't upgrade them too quickly. Also it seems that the size of the AI fleets has dropped since Entrenchment, but they seem to act more smartly.

As you said, the AI doesn't  take the starbase into consideration in their "Run Away Screaming Like a Little Girl" routine, which makes killing them with Torpedo Cruisers easy. Another thing is that they don't seem make use of the Torpedo Cruisers range when attacking my Starbases, i've managed to save many colonies by just ordering the Starbase to destroy the structure killers first, which come to range since AI uses them as a part of their fleet rather than a separate attack group.

Agreed and agreed. I too have never seen the abilities used by the AI, which is obviously a dissapointment and oversight. Also, the fleet AI does need to be reformed to take into account the cost of SB's and their tactical value, but it must be done so as to also take into account that the starbase actually needs to be on 'this side' of the gravity well.

Personally, I don't mind the number of starbases built by AI, as I tend to do the same, using the trade upgrades and culture ones (almost always play as advent) for every world, regardless of whether it is front line. Whether the AI is also doing this is questionable though, especially in light of their obviously not making use of the abilities upgrades (who is to say they are getting the economics ones?)

Hopefully these will all be addressed in this coming patch.. which I am very much hoping is coming out in the next couple of hours -- I have a long long train ride perfectly suited to Sins!

Just yesterday, i assaulted an Argonev starbase that had 2 bomber and fighter squadrons, over 10,000 HP with beams and missiles, so they do upgrade them atleaest to some extent. This was at an enemy homeworld, though, rest of the SB's in the system were less upgraded. (Systems of War map)

I also have noticed that AI fleet high tail it when combined with thier SB they could have matched me. I have also noticed when they attack my GW with a SB in it and a back up fleet not so big as their invading fleet they don't retreat until they are desimated. It seems as though they only take into account your fleet size and ignore the fact that there is a SB. So I guess it works both ways.