It's so great to come back to this book and, though I've only read a little, the extra details of seeing characters names and Kerouac's own sentence rhythms bring it to life in a new way. Plus I love all the details and extra stuff that fill out formerly minor characters.
The awful thing is the introductory essays. The first is good and well researched - it just tracks the history of the various drafts. The others are so pretentious and couched in literary theory jingo - intertextuality, text, deconstruction - and so laboriously written they're surely enough for Kerouac to take a benny, exhume himself and get back on the road and as far away from civilization as possible. (Although to be fair he's pretty far away from it under the ground, but hope you get the point.)
It's very funny, very ironic, when you think he was writing in reaction to the pretentious, elitist literary world that preceded him; and here his fine book is, at its rawest, preceded by these essays. No disrespect to the writers; maybe this is what was asked for and they can write much better than this, but...
Anyway, like I say the text - I mean book - is as good as ever; maybe better.
I'd like to add as a postscript that, since finishing the book, I believe this is a must for any lover of Kerouac's writing. There is tons of additional material and scenes and, really, this book in all its more-primitive glory supersedes the 1957 published text.