That sounds like a cool campaign. Our last game on FG was the Mad Mage dungeon by WotC. It was a lot of combat. One of the things that seems good about 13th Age combat in FG is that somebody else adds up all the dice!
I'm in planning stages for my 13th Age game now. We are planning to use the Engine of the Ages rules (from the Book of Ages) to figure out the prior history, so we are probably a couple weeks out from starting play. My group does like combat, so there will probably be a good bit of it, but we are also planning on only spending 1-2 sessions per level, so it will be quick, nonetheless.