i downloaded it and tried it out for a few hours ... bloody slow compared to default browser.
tried to view stuff on this site http://www.davidmovie.com/ and it lagged really badly, took about 10 mins to start the streaming then paused after 20 mins and wouldnt start back up, refreshed page and i couldnt fast forward by clicking progress bar at the bottom.

then used the default browser and it worked like a dream.

unless there are some big improvments i aint gonna use fennec again!