Hellishly fast!
Unfortunately it's got a few things to sort out before I'll be happy with it, on the iPhone at least:
* The default zoom/resolution on an iPhone is too large, so you can't read the text
* It seems to switch randomly between defaulting to 1:1 style zoom level and the entire page
* There's no proper zooming, just a gesture to switch between 1:1 and full
* Auto-correct doesn't work (it's surprising how much I used it)
I've always quite liked the Opera browser on the desktop and I think it shows a lot of promise but it's got some fixing to be done before I'll be using the iPhone version long term. It'll be interesting to see people's findings on the iPad one.
Edit: No flash. Stop dreaming