I thought that book 1 of the Wheel of Time series, The Eye of the World, was excellent, and I quickly picked up and read books 2 and 3. However, half way through book 4, I feel I must relate my experiences to new readers or those considering delving into this lengthy series of books.
As early as book 1, I experienced some minor irritations with characters, the way they were written and the way they acted. They were, though, only minor irritations, easily ignored because of the great story. By book 4, these irritations had become huge, and were seriously impeding my enjoyment of the story. I did a quick Amazon check on the reviews of book 5, only to find that readers were beginning to seriously mark the series down due to these specific annoyances.
In particular, Nynaeve's constant braid tugging, all the women's anger and annoyances with the men around them and the men's confusion over women in general, Mat's dialogue always starting with "Light" or "Burn me" and, a personally irritating one for me, Loial's grin always "splitting his face in two".
The above paragraph may seem very petty if you're just diving into book one, but these are huge books, and when key characters haven't evolved beyond these shallow characterisations when you're practically 4,000 pages into the story, then you might start to see why it can become an issue.
I truly wish I could read beyond these issues, as I'd love to see how the actual story progresses and finishes. I genuinely intended to read all the books in the series, and was really looking forward to a good, long fantasy series that I could stay with for a long time. Unfortunately, this has turned out not to be the one for me.
My recommendation: give book 1 a try, but proceed cautiously from there.