Opera Mobile is the real mobile browser for smartphones. However, Opera can't develop O Mobile for iPhone due to App Store's TOS.
Opera Mini can't handle modern websites using AJAX etc. because it can't render anything locally. It simply parses the data sent to it by the servers, which are responsible for rendering the website and compressing it.
Also, the speed benefits are significant, only if you are on a slow connection.
Also, the speed benefits are significant, only if you are on a slow connection.