What features does Opera Mobile have the Opera Mini doesn't? Are there any other differences such as speed?
Opera Mobile is a "full" browser performing all rendering activities on your Android device.
Opera Mini passes your requests through Opera's servers to render/scale/"tweak" for your device.
Opera Mini tends to be faster.
Opera Mobile tends to hit your device's resources harder.
Security folk cringe about Opera Mini and your traffic going through 3rd party (yet Opera) servers. Think about that before doing your online banking with Mini...
Read more in the comparison chart here: http://www.opera.com/mobile/features/
Size: Opera Mobile is ~20MB, Opera Mini is barely 900KB.
Rendering: Opera Mobile downloads HTML from web server and renders the website on your phone, Opera Mini downloads an optimized version (in Opera's Binary Markup Language/OBML) of the website from Opera's proxy.
Opera Mobile is more resource hungry, on Opera Mini many of the rendering task is done on the proxy server, which cuts the amount of processing, bandwidth, and memory requirement
Data Usage: Opera Mini downloads a OBML (Opera Binary Markup Language) from Opera's server, which compresses pages by up to 90% (according to Opera). Opera Mobile downloads the whole webpage from the original site, which can amount to quite a bit of bandwidth (note that Opera Mobile can also use Opera Turbo, which can also reduce bandwidth usage).
Last I checked, zooming in and out and rotating the screen in Opera Mini wouldn't reflow the text.
In short, Opera Mini is much faster and much leaner, which is especially noticeable on less powerful devices and on slow networks; however Opera Mini is not a full-featured browser (and is never meant to be). Opera Mini is much faster on slower network and slower phones.
i use nokia 5320 and i used opera mobile and mini opera mini is faster than opera mobile and low power consuption and less data usage opera mobile use more than battery and more than data usage opera mini is better than uc and other browsers so i suggest every one use opera mini when you have a limite data plan when you have unlimited data plan you used opra mobile .