I have the late 2009 model with 4gb RAM. My HD is almost full so considering upgrading to a 500gb SSD. But that will cost about $300 and I'm not sure if it's worth it. I have no need to buy a new laptop and only want more storage and speed. Does it make sense to put that much into a 4 year old machine? Other than the need for more space I'm happy with it but faster boot time etc would be nice. If I could extend the useful life of the Macbook instead of spending $1000+ on a new laptop I'd be happy. In order to get the kind of storage I want in a new MBA or MBP I'd have to spend hundreds of $ on top of the baseline model cost. Or should I just spend less on a new old-tech 500gb HDD?