I have to agree that the quick controls feature is pretty slick. Having used it, I will say, it's funny how something so simple can change your browsing experience so much. You get full screen browsing and can bring a quick menu up using a gesture. On honeycomb I got addicted to using it, I was glad to see they brought it over to the phone side now.
As for the scrolling being smoother in the iphone browser, I think that apparent "smoothness" is very easy to explain (and you kind of get to see what I mean in that video where the guy shows the scrolling). In iOS, you can only scroll but so far at a time, so the phone only has to scroll a very small section of a page at a time, whereas the browser in Android can scroll the entire page and therefore has to be able to render all of that while scrolling. In other words, fundamentally, the iOS browser has to do less work when scrolling due to it only scrolling through a limited area at a time. This is what delivers that perceived "smoothness". Personally, I don't like that limitation, as it is very irritating to me when I am on a long site (like engadget). I much prefer to be able to quickly scroll to where I'd like to go, than to have my scrolling MANAGED for me so that the phone appears to be smoother.