Or is Linux NTFS support mature enough to trust at least reading from it and hopefully writing to it too? Has that one man project stalled out and dropped off the face of the earth or are NTFS volumes something most Linux users deal with frequently now?
I don't know about the one man project?
But NTFS support has been pretty awesome for a few years now. I trust reading from and writing to it for sure.
A hardware RAID solution that is formatted with NTFS is what I would lean towards. I haven't done it, or researched it much... but I'd think you could do it.
Software RAID, forget it.