So the website here does not reflect this yet, but this card did receive an errata. It can only be used on a "connection resource". So no more cheap troubleshooter plays. That said, lets move on.
This card seems like a necessary evil to me. Using this card will almost always force the runner to trash that connection. And to use 2 and a to do it. Because let's face it, if they were going to play "tag me", they probably wouldn't have installed a connection (there may be some exceptions, like the upcoming Jarogniew Mercs). This is quite powerful, as you can get rid of some of the most troublesome cards runners have access to. And the reason it is so necessary is because there are certain connections that completely undermine a specific strategy you may be employing. Seeing Film Critic hit the table when you are playing as Haarpsichord Studios: Entertainment Unleashed elicits a sinking feeling. Ditto if you are playing a Midseason Replacements deck (if you are playing this kind of deck though, I advise you to stop, it is a stupid card). Aaron Marrón is going to give any tag-heavy deck a hard time, whether you are relying on said tags to flat-line or just tax the runner. So MCA Informant can save the day, and without the chancy psi game. Hence the 4 play-cost seems fair.
The evil comes in the form of its interaction with another card, namely, Zealous Judge. After playing MCA Informant, you can rez Zealous Judge as soon as the runners turn starts. They then basically have to do the following right away: Get rid of the Informant, access the Judge, and trash him. I made a deck specifically to see if this was as easy to win with as I envisioned. And I went 7 for 7. I made it in Skorpios Defense Systems: Persuasive Power just for the smaller deck size. Almost all runners drop a connection right away. Hide the Judge behind a Data Raven and/or a Chimera and they are going to have a real tough time so early in the game. After they try and fail, just hit 'em with a nuke. Anyway, seems a bit too powerful to me, so I will not be doing it again.