probably a bit off topic, but I do want to share my positive experience with the Crucial 256GB M4 in my 2011 17" MBP
I got the drive installed by an Apple authorised servicer, a cost I was willing to pay because I'm not all that familiar with the inside of Mac's and wanted to continue to have Apple support if anything went wrong (of course, though, they wouldn't cover the drive.)
Anyway, the drive was installed and had firmware 0001 on it. A firmware that apparently isn't actually capable with the 2011 MBP, so i was getting consistent freezing of the machine, beach balls, and could not at all use the MBP. I was quite worried and not too happy. I then rang Crucial and made it clear I wasn't too happy about their product. they told me to upgrade to the firmware and I did, still no different. So, I thought their was no answer, and was wanting to get rid of the drive, but because I purchased it from eBay, Crucial would only do a store credit for me, in which was not appealing, because I didn't want anymore upgrades.
So i decided to give it another shot, and wiped the whole drive, and reinstalled lion.
Since then (3 weeks on), i haven't got one beach ball and this drive absolutely flies, everything opens up so quickly, and hasn't crashed once....now running on firmware 0009.
Hope this helps/encourages some of the followers.