Stephen Leeds is a pretty cool character, though I must say, his hallucinations take the cake (J.C. being my favorite). And what I enjoyed about the first and second story is his relationship with his hallucinations. It's such a clever idea, the way Sanderson worked that and so much fun to read. 
 I only felt a little let down because things went a bit unaddressed. (view spoiler)[How in the first book the camera (being a pretty cool idea) was made a big deal of, and the ending, figuring out the flash aspect, was made a big deal of but was then shrugged off in the beginning of this book as not a plausible option to pursue. And then there was Sandra. This mystery woman who played such an important role in Stephen's life and, at some point, abandoned him and his hallucinations. So much importance was brought on her character, brought up many times in the first book and again in this one but never fleshed out why. Never really gave any answer or conclusion to her, just made you wonder why she left, who she really was, which for me took a bit away of this 'importance' of her role. Must not have been that important to fully address. (hide spoiler)] If Sanderson plans to write another maybe he will touch on those things. Until then I guess I'll wonder and just remember those characters and the fun I had with them.