So I've been thinking about replacing my iMac (Mid 2011) with a new 13 Inch MBA (2014).I've been offered a good deal for the iMac so I want to do it ASAP. I can either afford ordering one with 8GB RAM (instead of standard 4GB) OR with 256GB SSD (Instead of standard 128GB).. I cannot decide which upgrade will be worth my money,my current iMac has 4GB RAM and is quite alright for my needs but I'm tempted to have a 8GB RAM MBA as it's going to be my main computer at home. on the other hand,my iMac's 500GB HDD is around 300GB full,it's been like that pretty much all the time..so I definitely have to move some of my files into an external storage if I opt for more RAM which is doable but not very convenient. which would you say is the more important investment out of two? is 128GB SSD practical or is it just too small? is doubling the RAM on these MBAs noticeably improve the performance?