Having worked in a IR booth before the use of HD at the site where I work, I can tell you that using anything other than HD is wasting your time. The quality simply isn't there to help whatsoever.
I'll stand by my position that either you use the right equipment, or you've done a lot of work for nothing. Of the possible 1 or 2 reviews in a game, crappy equipment just isn't going to help much. Also, how are you going to stop the game, and communicate with the R? O2O? Possibly, but they can be unreliable as well. IR booths all use a paging system and the majority of officials will wear a pager. I don't mean to be such a naysayer, but I feel I speak from experience. You use the best system or you don't bother with it.