I have a simple question (or it might not be simple) about HDDs.
On a WD Caviar Black, Sata 6 gb/s or any drive, is there any
difference in Performance/Speed, Life and Problems between
Partitioned and unpartitioned? Simply which is better?
What do you mean by that? You can't use a SDD/HDD unless it has at least one partition so the question is a bit odd. Other than that there is no need to consider speed IMO. Data in the same spot is accessed equally fast no matter if it is on the first big partition or if the HDD has been partitioned to 2 smaller partitions.
Just think if it is convenient to use one single C: or if you prefer to have folder structures on separate partitions.