I don't use them. They are cheap. I set my killstreaks to something that will benefit my team. Lightning strike, AGR, EMP.
I'm not one of those who will complaing about the quickness of the Lightning Strike, but you call the VSAT cheap, but will happily use something that will kill a victim before they are warned. You will use a score streak that you can leave unattended that will get kills for you. And you will also use a score streak which will null an enemies HUD and bugger up whatever electronics they have AND remove whatever score streaks they have in the air without having to whip out the usual means of anti-air?
The majority of kill/score streaks in essense are cheap. XD