Hi - I've put a Crucial M4 512Gb SSD in to my 2008 Mac Pro (Lion), and it's transformed the old chap. However, I have had a couple of instances of coming down in the morning to find a frozen screen ...

But generally SSD firmware doesn't come out often at all, so I figure there's probably a good enough reason to go ahead and install it because they're not just throwing out pointless updates or ...