FWIW i use Clip Browser “Copy all” to copy all of the files from the SDHC card to a 1TB Internal Hard Drive on my MacPro. I use the CRC check which takes extra time but I am not usually in enough of a hurry to not check the data. On a few occasions Clip Browser did stop the transfer of the data. I assumed it was checking the data as it was supposed to. I did the transfer again and it was fine. I then change the file number that Clip Browser assigns to something that makes sense to me and use XDCam transfer to import the files from the 1TB hard drive to Final Cut Server. Now I have two copies of the files. Only now will I erase the clips.
I load a ton of clips everyday and have only lost one file to date (it was a static electricity event). It is amazing how many TB hard drives I am going through. I am considering LTO back-up for each drive but have not found a system that works with Mac.