Efficiency question: editing objects/materials verses replacing the object/material

Is it more efficient to modify the existing material or object over replacing the object/material?

for example:

an object’s material changes under certain conditions should I replace the material or just change the texture of the existing material?

an object’s type changes in such a way that you want to attach it to a different node should I detach from the old node and attach to the new or delete the old object and create a new one which is then attached to the new node?

My guess is it is more efficient to modify existing objects or materials as long as they are simple modifications over creating new ones.

Yeah it probably is but only marginally so if you don’t use bad VM’s like dalvik with bad GC. jME itself doesn’t “work more” because of the new objects really (save custom meshes and textures that are not loaded via the assetmanager).