You need to ask yourself 2 questions.
Am i a fan of Ghostbusters?
Am i fan of fun, creepy, atmospheric games?
If you answer yes to any of these, you need to buy this game and do it immediately. Its fantastic. As a fan, you just cant ask for anything more. This has it all. Its just a fantastic well made game that features some of films greatest characters and scenarios. I am surprised at how truly creepy this game is. I wont spoil anything, but there is a time when you are separated from the group and the following stage will have you on edge the whole way through. I highly suggest cutting out the lights and turning up the sound. I'm about 9 hours in and I'm on the final stage and its just been a FANTASTIC ride, absolutely fantastic.
As for any exclusives, i think the PS3 has a trailer for the Blu Ray and a little featured called restoring the Ecto 1 which is included with the Blu Ray. Other than that, there is nothing that really separates the two. Which ever system you use for online gameplay, get the game for that system.