Both of those expansions do something different than either vanilla ES or GoA, which is to stage your adventure into two different halves and throw things like extra timers, stage goals, and the like at you. Generally you spend Stage 1 facing easier cards and trying to bulk up your party for the harder Stage 2, in which you go about the usual business of collecting Elder Signs.
I don’t really care for either of them, if I’m honest. As @Infested_terran mentions, the staged nature of each game makes them either go on far too long or end far too quickly (as a poor showing in stage 1 can make stage 2 nigh unwinnable, so you just end up bailing on the game). I admire what they tried to do with the ES system, but I got rid of them both, as I’m perfectly satisfied with GoA.