I am looking at purchasing a 512GB SSD for my laptop. I have found a OCZ Agility 4 for $300, a Crucial M4 for $400, and a OCZ Vertex 4 for $450. It looks like both OCZ drives are faster than the M4. It looks like the M4 has been more reliable based on reviews. I have no problems doing firmware updates. I have been in IT supporting Mac, Win, and Linux since 1997. This is going in a Macbook Pro Early 2011 to replace a 500 GB traditional 2.5 inch HD.