Any specific ones you care to mention? You can always use the user agent to spoof it for that particular site. I've yet to find a site that isn't suported.
I love features like the voice tool that will read highlighted text to you. I can sit at work with a techie site open on a subject I want to brush up on, shade teh tex and click voice and it reads it out to me whilst I get on with work.
Or teh way that sites all have their own set of preferences so I can allow pop ups or images or cookies at a granular level very easily
or context menu (Right Click) that includes sensible options like search with and a selection of sites liek google, dictionary, etc
Or even a simple Go to URL option for where URLS are on web pages but not as a link,
Teh trash can to recover tabs you accidentally closed, thumbnail views of all tabs, teh list goes on
Also if your a keyboard person teh shortcuts are better configured ( Z is back instead of ALT Back Arrow.) One finger to rule teh world