Opera has long since replaced my browser of choice on my iPad and iPhone just due to it;s user interface working with me instead of against me.There are tweaks ahoy including better compression , share articles by email and now predictive text has been added as well. Another notable feature is the data counter (accessed by going to help, data counter) to show you just how much you are saving.
I'd argue that for internet savings when on the internet Opera is 1000% times better than Onavo (reviewed here) not only compression wise but for the fact you get to keep your soul away from the marketers and data miners.
Personally I prefer using Opera to Onavo as the Norwegian based company isn't looking to sell your soul to the authorities or data mining companies.
Also Opera seems more stable than Onavo when dealing with weak or slow signals but that's just my subjective view.
Opera is available from the App Store now.