A really powerful card and I suspect one of the main reasons MCA Informant exists.
What the informant does is make runs on assets without trashing them make credits. If you only have one informant that's simply a trade of a click for a credit. If you have two (or one and a Desperado) it's 2 per click, Magnum Opus territory. If you have all three out you generate a whopping 3 per run. Add Desperado and you can get up to 4. Add Temüjin Contract and things become really insane.
This does rely however on the corp having easy-to-access (read: unprotected) assets. That means Aeneas Informant is at its best against asset spam decks. If only those were popular...
Other decks do frequently run PAD Campaign as well though and even if the corp ices all their PAD Campaigns that probably makes it worth including 3 Aeneas Informants in our deck since it means the corp won't be able to put as much ice on other servers.
But Aeneas Informant doesn't simply work on naked remotes. As a bonus it also kicks in when you dig through R&D or HQ. If a Legwork is unsuccessful at finding agendas but does see some assets Aeneas Informants let you get some of your money back, provided you don't trash the assets.
At 1 influence shapers can get their own informants as well, which can be useful in an R&D dig. Just remember that you have to reveal a card to get the credit and thus give the corp some information about what's coming up for them.
From a corp perspective Aeneas Informant is not all that easy to counter without the right cards. MCA Informant is an obvious and very effective silver bullet. Best Defense simply works as well.