I'd gone through a Paddy-White-phase of my own, when I was in my late teens/early 20s, and read ALL of his novels including the really-hard-to-get Happy Valley (courtesy of the City College Library's Special Collection).
I really do believe the man could write.
His most psychologically acute novel is probably The Eye of the Storm; however, my personal favorite is A Fringe of Leaves--loved, loved, LOVED it--but then again, I'm a sucker for historical settings. The language was absolutely delicious though, as was White's usual mixture of visionary imagery and social satire. The last few chapters had me on edge.
Liehtzu--I'm sure you'll be glad to learn that interest in White's work is resurging in the States; in January of 2009 two of his novels are going to get special treatment from Penguin Classics, and I'm already in love with the covers: The Vivisector and (your favorite) Voss. At 10 bucks a copy, I'd say it's a great deal.
I once thought of writing a paper on White in my Postcolonial Lit class (some of his novels fit that category rather neatly), but gave up after a while and did Doris Lessing (The Grass Is Singing) instead--writing about White felt like trying to describe a religious experience--words simply failed me. I'm thinking of rereading some of his stuff this summer; I'll probably go with The Living and the Dead, which I always liked despite all the negativity, and The Twyborn Affair, which I find hilarious. (I wonder how many readers reach the second half of the novel thinking that...--but I'm not going to tell--DON'T read the jacket blurb, the stupid thing reveals everything).