Hi there, I happen to have a used MacBook 5,2, pre-unibody model that seems to be struggling a bit with the installed Lion (free upgrade performed by the store when I had a HDD corruption issue). True, it is completely stock, side for a third-party battery installed. It now sits as a homebound machine, where it runs Transmission, my Bitcoin wallet, a Freenet client, a Tor node, and my backup surveillance system, these kind of things that absolutely need to stay connected 24/7 for optimum performance. Hardware context: this is one of 4 machines, my daily-driver MBP, a LG PC (same power as the MB) I expect to use, one day, to offload videosurveillance task to (depending wether I'll be able to finally get ZoneMinder to work), an iPad, all linked through a WRT54GL Linksys router that's having stability issues on its own, occasionally with a gigabit switch. Usability context: feels slow. Very slow. Such a "feeling" may not be that important as I rarely touch it directly. Unable to stream a 8GB, 1080p movie, but I am not sure yet if its a computer or LAN connection issue yet. Can manage a 1.3GB 720p movie, but barely. This is a concern as I'd like to use my daily MBP to watch movies as it has a better screen but would rather avoid transferring it to its own local HDD first. So, would it be a good investment to double its RAM ? I don't feel too concerned about the internal HDD since most storage is external (desktop drives), but it may be the actual bottleneck. And how would I find where the actual bottleneck is? Again, I don't have hundreds of bucks lying around than some fellow Americans among you seem to have as these people will invariably advise to invest in brand spanking new high performance hardware.