That's going to be a tough one, because I think there will be different appeal. Just got Hobbit SE today - it definitely reminds me a bit of LOTR in terms of the ruleset and completing different quests. It's definitely going to be quite complicated when the code gets closer to completion. Ghostbusters I feel will appeal much more to the casual gamer, and have more of a "fun" vibe. I view The Hobbit as LOTR, and Ghostbusters as AFM. AFM vs LOTR - two very different games, but AFM is always going to be more "fun" to the casual/non-player because it's just so easy to immediately grasp the rules and what you are supposed to do. The Hobbit will have more of the "wow" factor and get more initial attention, but I think Ghostbusters will be played a lot more.
Again, this is all complete and utter guesswork based off of what we've seen of Ghostbusters. Who knows what both of the games will really end up being like once all the code is done and the games are out there.