Unlike a rifle bullet with a flat trajectory, with an unguided rocket you need to know the exact range, in order to hit a vehicle-size target. This is not usually possible in combat, not even today with the existence of laser rangefinders. That's why I don't think that unguided rockets are effective beyond 200-300 meters.
To illustrate this point, I once shot an RPG-7 at an old truck cabin in a live-fire exercise without a previous dry-run. It was only about 75meters away but I overestimated the range and the rocket flew over it.
So you don't think that this is simply due to me being a bad shot, in the following exercise I was supposed to shoot another RPG at a pyramid target of two barrels over three. To avoid another fadicha, my officer carefully paced out the distance to the target after the dry-run.
He told me that the exact range was 150m. I put the crosshairs right in the middle and shot. Boom, the rocket is off, straight at the pyramid but there is no explosion on the target. I couldn't believe that I had missed again. But one second later the two top barrels wobble and fall over. The rocket had gone right through the space between the two barrels and knocked them over them with the fins!
I also had the opportunity to shoot at houses at ranges no more than 100m with both the RPG and LAW and in neither case did I hit the house at the exact point of my aim.
I bet that most hits on tanks, even stationary, from RPGs in Chechnya, Iraq or Lebanon were taken at less than 100m. I read that in Vietnam, only 1out of every 7 RPGs fired at the M113s actually hit.
I think that the RPG-27 or RPG-7VR are more useful than the RPG-29 for a quick short range shot where a heavier and more complex system is impractical. (And at 8kg, the RPG27 is more convenient than the RPG7 + VR combo that weighs 11-12kg together) . For about the same weight as the RPG-29, you might as well take an ATGM system like the Gil with a much higher hit probability rate on moving targets and much more range.