My hard drive crashed on my MacBook Pro, so I have to do something. My MBP specs are: mid 2009 model, Intel Core 2 Duo 2.26GHz, 8MB RAM. I'll be installing a Seagate Momentus XT 750GB (SSD hybrid drive). Should I upgrade to Mountain Lion or stay with SL? I'm leaning toward upgrade because: 1) I assume SL security updates will stop soon, if they haven't already. 2) I would like Time Machine Encryption. Under SL's TM, can anyone plug the external drive with TM into their Mac or PC and access files on it? I just want to be sure my TM backups are secure. So don't I need ML for this? This is my driving reason for getting ML, so if they are secure on SL then I might not need ML right away. FYI, I don't need Rosetta, so that is a non-issue. If I upgrade to ML, should I install SL first(add my data or not?) and make a Time Machine backup before installing ML, just in case I don't like ML? or should I just install ML first? FYI, I don't have any TM backups, so I will be manually installing my data from a backup disk. I know this may be personal preference, but I'd be pleased to have your opinions and advice as I think about this. Thanks!