Hey Guys, I have the 21.5" iMac (base) model and was just wondering how much difference upgrading the RAM from 4gb to 8gb will make? The machine is by no means slow it was just to future proof it really. Also whats the maximum amound of RAM that can be put in this model? 8gb, 16gb? Finally which RAM would you recommend? I dont mind spending the money on it but not from Apple. As many of you know the price they charge for a upgrade of RAM is abit on the cheeky side. Also i work as an IT engineer so its not a problem for me to replace this. Cheers guys!