The latest firmware is 2.22; it came out in April. I finally installed it on my OCZ Agility 3 120GB a couple of weeks ago, and have had no SSD problems since, which is a great relief as on the previous firmware versions my PC would lock up every few days and need full power cycling before it could see the SSD again.
I still don't get anything like the "550/500 MB/sec" speed the OCZ spec promised - my top write speed is about 250 MB/sec. Turns out that you only get 500 MB/sec if you're writing highly compressible data (not real data which often isn't!) using the right Intel controller chips. My MB has a Marvell controller for the 6 GHz ports, which OCZ now say can't drive their SSD so fast.
So I won't be buying OCZ again, but at least the one I have now works.
I'm thinking about getting a Samsung 256GB SSD 830. Does that do what it says it does?