I bought mine yesterday and tried it out for an hour or two with several instruments. To summarize my impression: It's amazing what it does to the signals. A few quick thoughts:
* It puts signals in a room. If you have samples that are not very "in the room", you can enhance this by using Berlin Studio. I wouldn't consider it to be a substitute for a dedicated reverb like Seventh Heaven or Cinematic Rooms.
* It smoothens transients to a degree that I didn't expect. You can throw in blaring trumpets, piercing piccolo, bells etc, it will all nicely be smoothened out. Very cool!
* What it doesn't do: It doesn't turn a close/spot mic signal into a tree mic signal. I tried it out with Synchron Brass instruments close mic only, it still sounded way too thin. Going in with Tree/main mics produced good results.
* I compared OT M. Ark samples spot mic only + Berlin Studio with the original spot+tree mix and it's actually quite close, but more muffled/muddied. To be fair, I didn't play around much with the EQ settings which Berlin Studio also has a lot of. I think you can edit the hell out of the signal with this, but I usually don't do EQing mic signals. I'm a composer after all.

* What was interesting to me: While it sounds amazing with plate bells, with horns, with timpani, I wasn't so overwhelmed by what it does to (synchron) woodwinds. I think I heard some not so nice resonances. Might be EQ-able though.
* To finish off with a real game changer for me: The synchron percussion with close and main mics put through Berlin Studio had a lot of presence and sounded wonderful. The timpani was just amazing!
* Didn't have time to try it with CSS. I can imagine it does wonderful things to strings. Maybe someone else here can tell about that.
Hope this helps some way or the other. Have a great weekend!