Comment Go old school (Score 3, Informative) 210
What do you fine folks think?"
I think you're not a very well trained sysadmin.
There is no reason to not have various parts of the filesystem mounted from different disks or partitions on the same disk. If you do this, you can run part of the system on one filesystem, other parts on others as appropriate for their intended usage. This is commonly done on large servers for performance reasons, quite like the one you are asking about. It's also why SCSI ruled in the server world for so long since it made it easy to have multiple discs in a system.
So run most of your system on something stable, reliable and with good read performance, and the portions that are going to take a read/write beating on a separate partition/disc with the filesystem which has better read or write, whichever is needed, performance. If you segregate your filesystem like this correctly, an added benefit is that you can mount security critical portions of the filesystem readonly, making it more difficult for an attacker.
Red