All this occurred to me while watching video of the huge earthquake and resulting tsunami, which devastated northeastern Japan, drawn from both amateur and professional sources. Although I can't claim to have seen all the user-generated video coming out of Japan, I feel confident stating that most of the really compelling (and frequently disturbing) video was produced by professional news orgs - usually with no warning or time to prepare.
One big advantage the professional news outfits had in terms of resources was mobility and perspective - specifically the aerial mobility and bird's-eye perspective provided by traffic helicopters, which were able to turn their focus from congested highways to the approaching tsunami, capturing awful (but spectacular) footage of giant waves sweeping huge ships and mountains of debris over neat, orderly farmland and villages. As so often is the case, the most compelling footage was also the most terrifying, and some of the scenes were positively apocalyptic: a building on fire riding the flood tide into the center of a small town, an oil refinery in billowing flames.
By contrast, the user-generated content - while interesting for its man-on-the-street perspective - simply couldn't capture the scale of the event or the damage inflicted. Videos taken by regular folks out in the streets or in their offices appeared to show some shaking, but (no offense, amateur cinematographers) the usual fumbling of inexperienced videographers made it impossible to get a sense how much was the earthquake, and how much was the person holding the camera moving around. Likewise, amateur videographers tend to be a little too frenetic: because they want to capture everything, they keep on whirling around to focus on some new subject, before whirling back to see what's going on over there - and end up capturing nothing of interest.