although I do have partition magic I've not used it a great deal (yet). But when you start mentioning pasting data over I wonder if you are looking more for a different product... they sell DriveImage and DriveCopy too (neither of which tempt me).
If you're wondering about the internal operation - they claim it is safe, but in all these operations there remains the risk (in event of power failure or somesuch) that it could turn "Partition Tragic" and render your HD unuseable.... However probably marginally safer than trying to do it solo at low level without their recovery strategy (unless you are an expert, in which case right your own!).
Hope this helps - next post will be 200th I think, so I'll try to make it useful!