Uh, Mirror/UX does strip smaller sizes that PE (4MB). That is you can choose strips of 4, 8, 16, 32, or 64K blocks.
I have not done any performance tests though. It would be faster than not stripping and putting the same contents on the volumes.
Kevin Brock, OCP, MCSE / Senior Technical Consultant
Fullscope (formerly RedKlay, formerly QCI)
(Web & Baan Consultants)