Wow. This was an awesome ride. 
 some thoughts : 
 (view spoiler)[Too much time spent in Habitat, could have been condensed. 
 Loved Sentinel, but Elspeth didn't really use her powers and she never said "Here be dragons". 
 I think a lot of unanswered questions about Dragon (towers, spectre etc) will be snswered in the beforetime chronicles 
 golator, dragon's book... these were never utilized so why include them? 
 Maybe I'm a dumb dumb but I would liked to have had a final "these are theclues I was given, here's what they ended up corresponding to. we've spent so many books on the search for them, I needed a round uo 
 I think I like the ending if Sentinel can connect to the other computers. she's out ofhl human drama (ie still going to be a struggle in the land for misfits)but can still contact friends. (hide spoiler)]