Call me biased since I've never listened to the revival recording, but I would take a full sized orchestra playing Sondheim over 12 actors playing their own instruments any day of any week. You'll also have the songs, and interpretations as they originally were meant to be. Once you've familiarized yourself with that, listen to whichever recording you'd like.
What annoys me about all this is that orchestras are always another character in the show. Composers, score writers and orchestrators write for a certain amount of musicians and instruments for a reason. Taking them away takes away a whole character and meaning for the show.
Case in point with the recent Sondheim revivals. The new Sunday production had 5 players in the pit. Not only did it sound tiny, and not do justice to the score, Sondheim and his orchestrator Michael Starobin chose to have 11 musicians in the pit, because Seurat used 11 different colors while painting Sunday on the Island of La Grande Jatte.
Or, the Sweeney revival which had 10 tinny sounding actor-musicians. Talk about taking another character away from a show when you decrease the size of the pit from 31 to 10. So much depth, and emotion, excitement, and thrill is lost when you take away that huge sound.
Oh yea...pick the Original cast recording of Company.
-There's the muddle in the middle. There's the puddle where the poodle did the piddle."