Hi all I have an iMac early 2009 20-inch model with 2.66GHz processor and 320GB 7200-rpm Serial ATA hard drive, originally came with 4GB RAM. It was starting to become slow last year so I upgraded the memory to 8GB ram which helped. Once I upgraded to OS Mavericks it is now becoming slow again. My primary computer is an MBA 13" Mid 2012 and I use my iMac maybe once a week or a fortnight (especially in the last 2 years), and only use the iMac if I have work stuff to do (need to draft a report etc). I notice that the display is markedly different and after about 30mins starting on the iMac display I do get a headache and need to rest for a bit. Other issues with the iMac I guess is the USB 2.0, would prefer USB 3.0 for backup reasons/cloning hard drive etc but this isn't a major issue at the moment but could be in the future. MY concern though, is that I don't want to continue using this iMac until it breaks down, and would prefer to sell it for some money while it is still working. So my current question is: I'm planning to sell my MBA to buy a 13" Retina MBP that has just been released (I renew my MacBooks every 3 years anyway); I did consider the 12" Macbook but I only take my computer out of the house when I am on a long vacation (so maybe once a year). I am very tempted to sell the iMac and buy a newer iMac - I can get a 21 inch late 2014 iMac for £700 (second hand on Amazon); but as I stated I don't use it much so not sure if the money spent to do this is justified. Should I just plunge for this, or should I maybe just get a large display monitor instead so I can use the large screen to do work stuff through the shiny new MBP? Any advice is appreciated!!