I have a 6 month old iMac with 2 gigs of ram that has been performing beautifully. However there is this nagging voice in the back of my head saying "why have 2 when you can have 4". Problem is, I dont feel all that comfortable laying my iMac face down and diving right in. I'm I just being paranoid? Is it really a simple procedure with minimual risk? Is it worth it?