Mozilla with the Pinstripe skin is a decent looking browser. Not quite as beautiful as OmniWeb, but better looking than iCab and Opera, and almost as Aqua-ish as IE.
My major beefs with OmniWeb are it's lack of support for standards. 90% of the websites I visit it handles fine. But it can't handle my online banking at all (Wachovia), and other sites like Foxsports.com gives it fits as well. Not to mention shockwave.com and Flash intensive sites. It's Flash support keeps getting better, but it's still not at 100%.
And probably my main beef with OmniWeb is it's instability. While each SP build achieves more stability, for me, the application is very crash prone. I rarely can go 10 minutes without it crashing. That is the one issue that finally drove me over to Mozilla full time. Mozilla is uglier, it's application responsiveness is slowner than OmniWeb, but it renders pages correctly and faster than any other browser out there, and it is rock solid - definitely the most stable of all OS X browsers.
OmniWeb definitely has a place in the crowded OS X browser field right now. My concern is that in 6 months, when Chimera (Navigator) gets up to speed, what will OmniWeb have to offer that other browsers can't?