Wikispaces v. PB Wiki

I am more familiar with PBWiki and so I'm inclined to say I like it more, but I want to give Wikispaces a fair chance. I did like it. Both PBWiki and Wikispaces are very user friendly. I found that the introduction on Wikispaces was very nice--it popped right up after I created my account so I didn't have to hunt around for a tutorial or anything. And it was very thorough--possibly more so than the introductory info on PBWiki. But again, I didn't need much of an orientation to PBWiki. Both of these sites, however, are wonderful and would lend themselves well to classroom or school library needs.