Offense or defense?
[link|http://www.emergency.com/rpg7.htm|image]
If you're aggressing the site, you'd use the RPG's make holes in buildings so your troops could go in. You might use them to take out snipers, but that's unlikely. You make a nice target when you're firing one of those. Think back to any war movie you've seen with a guy firing a bazooka. A guy with an M203 would do better in urban conflict than a guy with an RPG.
If you're encountering sufficient resistance to require that kind of weaponry, fall back and call in artillery or let a tank go first.
On defense, you'd use it to take out the aggressor's heavy equipment (tanks and APC's). But the signature means that you're going to draw ALL their fire. Using these against troops is difficult (unless they're formed up and marching).
Remember min/max. Trade the life of one guy with an RPG for one tank and crew. If you start trading RPG's for regular grunts, you're going to lose the war.
