> even though it came with a tremendous write speed hit
Only on a writes < stripe. If your writes are bigger then you can have way more speed than RAID10 on the same set, limited only by the RAID controller CPU.
Due to network limitations and contract budgeting, I never got the chance to upgrade them to 10 Gb, but can confirm I could hit 1000 Mbps (100+ MB/s) on certain files on RAID-6. It sadly averaged out to about 55-60 MB/s writes (HDD array, Buffalo), which again, for this use case was acceptable, but below expectations. I didn't buy the unit, I didn't design the architecture it was going into, merely a cog in the support machinery.