Remove old stucco or add on top?

We are looking at re-doing the exterior of our home. We have had several contractors come by and are receiving very different advice regarding re-coating stucco. About half recommend stripping off the entire stucco coat, while the other half claim we would benefit from the additional R value, and suggest leaving it on, using an acrylic bonding agent adding a layer of foam insulation and re-applying after that.

The home is a 1973 build and I believe it likely that the stucco has been painted. We had one leak (while replacing our roof the tarps blew off). There is not any visible discolouration.

We would prefer not to have to re-do the siding in a few years if the stucco bonding doesn't hold.

Advice regarding re-covering versus completely stripping the exterior?

Thank you,

John