I recently re-read The Integral Trees recently having first read it in 1985. I remember enjoying it as a teenager, but now in my 40's the book has proved just as good if not better. Compared with most other Niven works it's quite different in that after the initial scene setting it rushes along providing a roller-coaster ride for the main characters. Is is minimalist in terms of the descriptive narritive but enough to keep pace and make you care about the core players, almost like a movie screenplay. It's an easy read and a good book even if you aren't a hard sci-fi fan.
Couple of down points, much of the action is a bit too coincidental with major events overlapping for no real reason. Some of the female characters seem to be copies of each other and some of the cultural concepts are re-visited too often. Not a major problem though.
It makes me cringe to say this but if you liked the story in Avatar, you'll love this book as it carries many similar elements about the arrogance of technological societies and how civilisation tends to corrupt.
All in all, in many respects better than Ringworld, more convincing that Dreampark but with better elements of both.