I read the whole thing cover to cover (minus the appendix notes, which I merely browsed). And as massive as it was, I was genuinely sad when the last page came. That's all I'm ready for volume two right now.
I feel so fortunate to be alive in 2010 and get to read these words Twain didn't want published until 100 years after his death. Actually, much of it has been published before so there was a lot I was already familiar with. But it was almost magical to read Twain's thoughts, musings, and more-than-occassional ramblings that have never been made public before. When else does this happen with favorite artists, musicians, writers who are long dead Almost never.
Twain is all over the place here -- the topics are random and far flung. But his voice rings true on every page. His lovely, cranky, cynical, hilarious, insightful, entertaining, voice. I simply can't get enough.