Because the SSD option on a 27' mac is a ridiculous $1300 i'm considering a Fusion drive. I know a Fusion drive puts the stuff you use the most on the 128gb SSD part, But what if you need data from the other half? how fast is the other half? Is is at fast as a normal 7200-rpm hard drive? or maybe even slower? In that case i rather have a consistent speed. I'm also afraid if you use a lot of different files and the Fusion drive is always busy swapping data from the SSD part to the normal part the benefits of the Fusion drive quicky become disadvantages.