Actually it isn't as bad as I thought it would be. I generated 207 pine trees with the S-Replicator, it used about 93 Mbyte of RAM. I then converted them all to "real" instances and my memory use went to 98 MByte.

It does slow down (gouraud) display speed quite a bit though. So I changed the display to wireframe, and that speeded it up. Going to box display really made it fast. I then converted 317 pines to "real" instances, and memory usage was still ~100 MByte.

Converting instances is very handy for precise up-close manipulation of small groups of objects, and seems to be (IF you have a powerfull PC with a decent video card) quite practical. I really like that flexibility.

BTW, you can populate a sphere with Carrara's replicator, and do some interesting distributions with precise distribution shaders.