Thanks for the replies guys.

From what I'm gathering, it seems that the Discover More card that I have does provide a better selection of higher grade "% cash back" offers in the 10-15% range than what I can find in the Chase UR store. Chase does offer plenty of good rewards though.

With the Chase Sapphire preferred however, the 25% bonus you get when buying airline tickets through their portal is simply devastating. I just noticed that their price aggregator includes Spirit airlines, which will be great (more like a necessary evil) for my low budget travel plans. Combining that with the rotating category bonuses of the Chase Freedom, really seems like the way to go. I will continue using my Discover More card however, when really good promotions come around like the 2% cash back for bills they are offering for the rest of the year.