I have used omv in my test lab here and at home a bit. The test lab it worked well, but i just ended up using ubuntu and iscsi when i had to put something in production. omv just has a web interface, some plugins to turn on. Sort of like webmin lite but for only storage. Development seems active; they keep producing new builds.
At home i installed it as a vm for a bit but when i broke my Xenproject i ended up reformatting that drive and omv with it.