It should work fine, but the range won't be amazing nor will the video quality. A directional antenna on the Rx side will help, but the video quality is still not awesome. Unless you're showing video to the crowd real time, streaming it online, or using it to help find your rocket, my gut says you're better off just recording with an onboard HD camera of some sort.
Haven't tried a diversity receiver yet. I send the video to a 42 inch LED via my laptop which sits in the back of my SUV on launch day and serves as a dual monitor. I hard wired a 1000 watt pure sine inverter to run all my electronic crap right from the back of the SUV. Works pretty well. Have had great success with my flights so far.
Ordered one of these to play with but haven't got around to it yet: