On a related note, RAID rebuild failing on slower drives is ridiculous these days. Is it so hard to implement something like buffer underrun protection in CD/DVD writers? Or just longer/adjustable wait times?
These issues mostly crop up with hardware RAID controllers that were not designed for anything like that. And what you'd need is actually the opposite of buffer underrun protection; you have to protect against congestion, whereas having the drive idle would not per se be an issue.
The enterprise hardware RAID controllers have battery backed memory that is heavily utilized during a rebuild. Operations that would take days without it are reduced to hours. I'm not sure what a typical NAS does though.