In my last big package of games I got Elder Sign, and my wife noticing it also decided to order me Unseen Forces with some Amazon cards she had.
So now I have both, and I have a Revised Edition, but I was wondering if I should start playing with Unseen Forces right away or not? Other than a particular AO and its monsters, and bless/curse, it appears that it's an expansion that just adds more of everything to the base game. I've already played a few times now and have plenty of games(due to AO/Investigator combinations) left before I really feel the need to mix in the new content, but is it anything all that different that I shouldn't just combine them now?
Also, since I have correctly printed cards AND the replacement cards, should I leave the replacements in and just have some dupe locations?