This is from a forum I'm on, and I'm glad I saw this before buying it:
So just a heads up for those wanting to have this "on disc"...it's not. The disc is just the installer files, it copies them to your hard drive, and you launch them from the XMB as if you bought them off PSN. But get this: You can't launch them from the XMB without the disc in the drive.
The soundtracks and art can all be exported to your hard drive. You get a code for 24 avatars, 8 of which are Journey and not on the store. There's 3 dynamic themes - flower, Journey, Journey concept art. First two you can buy on the store I think, but the last one I couldn't find.
The dev commentaries are just videos of the game with dialogue of them while playing and subtitles.
There manual includes about 8-10 pages of behind-the-scenes stuff too (not art, like how the GameJam happened and about the Team behind TGC).
If you don't have any of the games, then this is a really good deal. If you already have 1 or 2, I can't recommend it unless you're just a huge TGC fan/supporter.
Edit: And you get a month of PS+ too, so...there's that.