I think every now and then you might get a message saying your spies have stolen a tech, and the tech completed screen comes up. Other than that, espionage is rather useless except for being able to see your opponents planets in the planet screen and the stats, as far as I can tell. If you invade a planet you are likely to steal techs also, and that without espionage. I never use it anymore and consider it a waste of money. The only thing I really need to see is what weapons and defenses are on their ships, and that I can see just by clicking on a planet or ship of theirs.

Never happened to me. To be honest I usually even do not bother with espionage. I can see what ships they have and that is enough for equipping my fleet.

I use espionage along with Planets listing sorted by social remaining time
then I go all the way down the list

that way I can see turn by turn, what the computer is building
sometimes I see a unique building here , so I rush build mine the turn before he completes it

I have been trying it lately but you barely get to steal anything. It does happen but rarely. It should be harder to get to advanced and then it should allow you to steal more techs quicker.

If possible I pretty much use espionage on every game, starting from nearly the beginning on one civ at a time, it doesn't take long to get it up to advance if you have the slider max out, and once you reach advance you can cut spending completely and still get all its benefits, including stealing techs, so there are many games when I have ended up with much more advance techs than I currently had, possibly because I did it from the beginning though.

Edit: erm, never mind. Wrong thread...

i don't know if it lets you know but i think if done it once or twice but i only use espeonage or however it is spelled when i expect a long slow war with a big race

While playing in the beta patch atm, the rate of tech theft seems to be up for me. I have been stealing tech from races that I am neutral with or worse every 10 turns or so. Also once I conquer a planet I immediately get a tech theft. That has happened everytime since this beta patch was installed.

42 tech's stolen last game - rare planets /rare stars large galaxy.. sure, a bunch of em were stuff i didnt need, but stealing black hole gun midgame helped diversify my missle-based fleets. what does seem odd though is that even when you come close to or completely max out spending.. you still dont seem to steal techs faster. were talking like.. billions of credits here, what state sponsored scientist in the real world wouldnt think twice about that kind of cash?

with that being said, being able to browse your opponants planets and deside which to invade first does help, the ai has a tendancy to put special building types just about anywhere - cutting out thier hyperion shipyards or the logistics building gives you a tactical advantage, at least in theroy