FYI:
Celemony is aware of the problems with Melodyne in Cubase.
They mailed me that they are looking into it.
Hope to see a fix soon for the Cubase crashing i get when deleting Melodyne from an Audiotrack.
I work with Cubase 7.5.1 - 64 bit, on OSX 10.9.2.
Hope to see some good (honest and real) performance comparisons between Cubase 7.5.1 - 64 bit and Logic X.
Best,
Robbie