I do my first checksumed backup, then run them through red rushes at 1/8 to make sure they transcode fine. If you get an error or drop frames, you'll know you've got some hairy footage. The checksum only really helps validate that the data was copied correctly. So you could've copied corrupted data correctly. I do my other 2 backups while redrushes is running.
Unless you need to use a Red drive to keep up the data-rate, shoot on CF cards. They are faster to format, faster to backup and more reliable. I really, really, really do not like to use the red-drives. There is nothing comforting about a spinning-drive that has most likely been reformatted over a thousand times, used in heat, cold, dust and shaken. :wacko: