OmniWeb 4.0 is out of beta, the full release is now available for download.
I've been using OmniWeb since installing Mac OS X and I love it! I find IE for OS X ugly and slow in comparison. OmniWeb's Quartz-rendered text is beautiful compared to IE's yucky QuickDraw-rendered text.
My favourite feature: When you click-and-hold or right-click on a hyperlink, one of the commands in the contextual-menu is "Open link behind this window". Brilliant! I can open 10 links on a page in separate windows without having to switch back to the originating window again and again.