ok I have installed it and on the surface it hasn't changed a lot, visually it looks exactly the same. one nice touch I have found is the ability to set opera as the default browser. This is a very useful feature. it means any web content requested by an application will use opera as opposed to Chrome.
unfortunatly I have had two crashes since I updated. I re-started the handset and it hasn't happened since.
in terms of speed, I don't see any diffference between this version and previous versions, but it is still blindingly quick. my tests show it to be three times faster that chrome.