Julian May's "Saga of the Exiles" series beginning with "The Many-Coloured Land" was fantastic and inspired my in so many ways, but I cannot say the same of the "Rampart Worlds" trilogy. I read these 3 books during a holiday this year and was really disappointed with all of them. In short, I found the characters shallow and the plot to be unimaginative and somewhat predictable.
Perhaps I've been too spoilt by the writing styles of other authors such as Stephen Donaldson and Iain Banks, where you really get to know the characters good and bad sides, and you can't say for sure who is going to be left standing at the end. In contrast, my overall feeling of this particular trilogy is that the good guys were too good, too polarised and there were no real surprises. Its difficult to describe, but I found the same problem with recent books from Raymond Feist - the early books, especially the "Empire" series, were great, but the later books are devoid of depth.
When I completed the third book I honestly felt that I had wasted all those countless hours. I left them all at the holiday resort not wanting to bother bringing them home, and that's a first for me.
I would recommend to anyone to read the "Saga of the Exiles" and the "Galactic Milieu" series from Julian May though. Then try Stephen Donaldson's "Gap" series.