First off, I have a non-unibody may2009 MBP, 2.93GHz, with 250GB HDD running SL. I'm planning on buying one of the Intels, and having the default HDD store media in the optical bay. My questions are thus, When accessing raw data (say a music file),does the HDD have to spin up to load the file or is the HDD constituently on? If it does have to spin up, is it a long load time? If it does not, is there significant power consumption or heat given off as it would be on constantly? I'm wondering this essentially because I have around 80GB of necessary data on the HDD, making the decision between 160GB and 80GB tough. Please, no banter about whether or not I should get the drive. That decision is made. I'm interested in this community's opinion on whether or not it is a good idea to save some money by using the 80GB as a boot drive, and storing the rest on the 250HDD, or if storing on the 250GB will be problematic, in which I would just get the 160.