I'm in exactly the same situation, and am very glad to have googled this posting. I have an question regarding one of the followups...
"There is one exception to the ability to grow a virtual disk; if you raid 5 was split into 2 virtual disks (e.g. 50GB for a boot drive and the rest for a data drive), you cannot grow the raid 5 set."
Now my RAID 5 volume is listed in OMSA as a single virtual disk. However, in the Disk Management MMC, that virtual drive is partitioned into 2 logical drives. Can this array be expanded?