There are many reasons to consider video depositions. If the witness won't be present at trial, for example, the jury will appreciate being able to watch the deposition on a TV monitor, as opposed to having it read to them by lawyers. Even when you know the witness will be present, a videotaped deposition can be more impressive as a vehicle for impeachment than the alternative. Some judges will even allow portions of videotaped depositions to be played during opening and closing.
Here's another reason to consider videotape: it will have the effect of making your opponent strangely silent, even if he's apt to be irrational and abusive when the camera's not there. He'll still make objections when appropriate, but they're likely to be made in a much more even tone of voice, without all the histrionics. Think about it next time you're matched up against one of your city's savage beasts.