Personally, I enjoy both sites. A lot of work goes into them, and it shows.
Of course I can only speak about the threads that interest me here. Of those threads, Amigaworld generally has much quicker responses to news and forum posts for some reason, but a lot of it is quick "great, grand, and thanks a lot" type stuff. AO generally has slower and fewer responses but they seem to be more insightful and more thoroughly organized. AO doesn't have the initial onslaught of the congratulatory-type posts that AW has. There' s nothing wrong with that necessarily, but to me the congratulatory messages should be kept more private.
I love the Amiga and have no real preference of one site over the other, but recently I made the "mistake" of voicing a simple observation about MorphOS hardware as it compares to AmigaOS and its hardware in an AmigaOS-oriented topic on amigaworld and got a tasteless Abuse threat for voicing such a vicious pack of facts. And that's fine. I just find myself somewhat less interested in Amigaworld if such a position of silencing any opposition is to be taken by its most ardent supporters. Silence speaks volumes.
I also wish there weren't quite so many spelling errors, but far be it from me to be the grammar police. It's not that I'm pedantic or anything. It's just easier to find things with search tools when all the nouns and verbs and stuff have been spelled correctly. :-)