'''1st Answer: NO you need/want SATA II or a 3GB/sec transfer speed.''' ''No need to pay for more, and some that claim they are "backward compatible" don't really play well at the slower speeds.''
'''2nd Answer: I think''' ''something in the install of 10.8.2 for the MBP omitted drivers or extensions needed for the iMac...'' updating (repair/reinstall) the while connected to the iMac should fix that issue.
''If this answer was helpful'' '''please remember to mark it accepted'''.''