I'm a fan of long books and longer series - gives me something to look forward to!
Unless it's Wheel of Time.
I don't mind when authors get a little excessively descriptive. It's a habit beaten into me by suffering through long feast chapters from Brian Jacques as a child (and, now that I think about it, I'm just reinforcing that with George R. R. Martin...) Wheel of Time took that to the next level. Do you like to have a picture of a character painted in your head? Down to the outfit, I mean?
Would you like that for every background character?
Every time they travel, there's a solid paragraph used to describe local fashions, I swear...
For me, that's not the biggest problem, though. I can't get past how he wrote women. Most of them seem to be the same character, and that character is pretty cranky. There's some exceptions, but the general rule is that most conversations between men and women are going to include back and forth sniping about how one knows what's best for the other, etc, etc. It's just painful to read through. Apologies to any fans of the books, I know a lot of people liked them, but I gave them a shot and they did not improve for me.
I'd second the Malazan Book of the Fallen recommendation instead, if you're looking for something new and lengthy and you have yet to read it. That's got its own hangups - Erikson writes the first novel like someone teaching you how to swim by dumping you in the deep end of the pool - but it's a much more interesting and readable high-fantasy style world. Also a good bit darker in tone - although I think it keeps to the same 'cosmic magic scope' that the later Wheel of Time books I read seemed to be moving toward.
I'd second the Kushiel books only if you're looking for half-historical fantasy, half medieval BDSM romance.
I can't remember anything about the Liveship Traders except thinking 'Wow! Neat concept!" But it's been years since I'd heard of it and I think I only read the first one anyway.
Bottom line - if you want to try it, more power to you! But don't feel bad if you don't like it, I think there's just as many people who didn't care for the series as there are big fans.