All of this works great. Stickmount is very nice for mounting and unmounting the drives, my 8gb test movie played easily, and I even tried plugging in my 500gb USB drive to see if the tablet would deliver enough power - it's perfect.
I cannot get Stickmount to mount FAT32, eFAT, or NTFS. Only FAT/64KBsector. How did you mount that 500GB drive?