Strange. I updated to 000F which gave me a big jump in write speeds which I was very happy with. I stuck with 000F as after reading up on the next update, it was clear that sticking with 000F was the smart move.
Very happy with my old M4.
This was the problem, I upgraded from 000F only to have 2 drives hit the drive not recognised by BIOS issue and although I managed to rescue one by downgrading, the other drive died and had to be RMA'd.
The Crucial forums have a ton of users with the same issue with 04AH and now with the latest upgrade which is suposed to fix it the same is being reported.
I moved to Samsung and won't look back. I don't need benchmarks, my photoshop and games launch quickly with whatever SSD/SATA combination, reliabililty is king now.