Some months ago my Macbook Pro started freezing. Pretty annoying really, and it happened after I had just installed Mavericks. Using the Apple Hardware Test I was able to pinpoint the fault to the SSD that I had installed by myself, Crucial M4 256gb in fact.
I thought the disk had just died. It was out of warranty so I thought there is not much to do except discard the drive. So I restored from backup and put the old HD back in. And then Mavericks was so slow that I found it impossible to use. Since I didn’t feel like shelling another 300dollars for brand new SSD, I just thought I’ll bear the situation.
Just today, my friend told me that he had exactly same situation with his M4, and that he had found a fix. In fact there is a firmware upgrade for the SSD drive, a neat bootable disc which automatically upgrades the firmware. I did it, and everything is working fine again! And really really fast.
I really love Mavericks, this is really speedy OS and feels in many ways snappier than earlier versions. Apple is really making big improvements for the operating system of Macintosh. After Snow Leopard, Mavericks is definably my favourite one.