If you want to see cloaked AI (armor only I think) then download turn 60 from my map6 game in the scenario/mod archive maps and scenarios. You will not see them unless you have put up sensor sats, which I did. Put all the AI on player control and check the ships list for ships with circles around them - those are cloaked. IIRC the first armor cloaking was around turn 30, but the game is dead and gone for me, of no further interest....