First duplifaces test using cycles. In total 100 characters, 10 different duplicated 10 times each.
GPU user: Nvidia 450GTS with 1GB DDR5
statistics (memory used / total time / time cycles preparing the scene)
with duplifaces: 118 MB / 55 sec. / 3 sec.
with normal duplications: 282 MB / 1.05 min. / 16 seg.
Clearly with duplifaces cycles uses a lot less memory and take a lot less time to prepare the scene before rendering.
More tests to come before the final test (an entire city).