I've been using the beta for a month or so, and it's miles better than the stock Android browser. Notable features:

- supports <video> and <audio>

- fixed-size divs (used for multiple scrollable page sections) work properly

- Pages are rendered practically identically to desktop Firefox/Chrome; the Android browser sometimes does weird things to pages with complex CSS.

While I haven't noticed any improvements in page rendering speed, but the browser UI itself is more responsive.