Yes, I recently lost one war in a multi-player game just because I didn't have an RPG model in time. I tried to field AT guns, but they are too costly to produce for the entire front, their mobility and readiness loss for movement without APC/trucks is an issue too.. Later when I managed to get my RPG infantry, things started to look better for me and worse for enemy tanks. It was too late anyway to turn the war, but that's a different story.
Had a similar experience with them in a couple of other games too.
AT guns are still great when you can afford them en-masse, that's true.
PS: I Also haven't tried yet how Micro-Nuke RPG look now after the nerf, but they used to be an ulimate weapon of destruction, extremely powerful agains infantry and tanks alike.