I played once with the new deck only, then mixed them in with my other Special Buildings. I have peeked at the dealt Special Buildings to ensure that at least one or two LGH cards got into play, which is easy to do with the distinctive face. I recommend hiding the cards when you use the Marketplace, otherwise it's easy to tell if they are LGH buildings or not (light passes through the original cards much more readily). If I know LGH cards are coming, I go to the Marketplace to see what they are, because they can be game-changing.
BTW, by 3:3 he was saying that deals three LGH cards and three original cards to make up the 6 dealt at the beginning of the game. (...and your curiosity was "piqued.")
Thanks for the insight and correction Dan, I just got my LGH deck and am looking forward to it hitting the game table soon.