I loved it. As much as I freaking adore the cosmere books there is something special about his non-cosmere stuff.
Also I just thought it was awesome how he took the popular Superhero thing at the moment and flipped expectations. I know it might not have been intentional since he's been cooking up Steelheart since '07 but I got a kick out of it.
Throughout the book I'd been getting vibes that "Megan was a Epic, no wait - Prof's the epic, no no, it's definitely Megan - well they both can't be Epics!" ad infinitum. I really liked that they both were as it punched my expectations in the face a bit and they were knocked out cold when it was revealed that Megan was Firefight (a metaphor worthy of David if I've ever seen one).
Can't wait for book two, I'm really interested in how being an Epic changes their DNA and this stuff about Mitochondrial mutation after death is interesting. And why do their personalities change when they use their powers and...so many questions. damnation you Sanderson *shakes fist*