I often use a flash bracket while shooting weddings. I used it all the time, for a couple seasons, then I didn't use it for a while, now I'm back to using it again.
The main purpose of using the flash bracket, is so that the flash is centred over the lens in both portrait and landscape orientation. I have experimented with several flash accessories, most of which are meant to be used while bouncing the flash. The problem is that without a bracket, the flash is still off to the side of the lens when the camera is vertical...and even when bouncing, you can still get the dreaded side-shadow.
There are two main types of flash bracket that keep the flash above the lens. A flip bracket and a camera rotate bracket. I've never used a camera rotate type, so I can't say how well they work. The bracket that I use, is a Stroboframe Press-T. I choose the Press-T bracket because it's made so that you keep both hands on the camera, just as if the bracket wasn't there. I guess, that with most brackets, you hold the handle with one hand and activate the AF/shutter with the other. But with both hands on the camera, I can still use the zoom/focus rings on the lens.
There are certainly pros & cons. The pro is that you can always keep the flash above the lens, throwing the shadows directly behind and below your subject. The con is that it makes for a big heavy rig...and that can be a major concern while shooting a long event. I use two camera bags, on is configured so that I can drop in, as one unit, the camera with lens, bracket & flash. That way, it's always ready to go.