personally i think briefing and fly are about even. fly seems to have a breaking news headline that comes out pretty early once in awhile whereas briefing hardly has any.
i chose fly because i like their interface better although loading the news scroller takes forever and drains my computer's resources.
if i had the desktop space, i'd probably get both since they are fairly cheap. but of course, you get what you pay for. i always get a laugh when a rumor pops up on flyonthewall and the rumor is obviously over 1 hour old based on the breakout on the chart.