I'm a fan of the system and mechanics to be honest. It's a great techno-Mythos set game.
As said previously, it can work at many levels, from investigations, espionage, military, mecha, X-Files. Depending how loose you want to be with its story, you've got quite a lot of space to work.
If anything I do find that the Sanity rules are a little rough on players. Yes, this is the Mythos, but on the same side, I feel the party group could do with a little hand in that area. They're quite vicious.
I'm lucky enough to have the books and screen. I will also add, the Game Masters pack was one of the better ones I've seen. It's not up there with the Runner's Toolkit, but still pretty damned good.
I do appreciate the mechanics are a little odd, next to the usual, not only for the poker like mechanics, but a few other elements as well. To me it's an engine, it does what it needs to do nearly all of the time and I've not felt a strong need to house rule issues away.
That which I did, it was the Sanity, I've got some notes down on letting the Hobby skill take away from the amount of stress the character is under.