In the market for an external HDD for my MBP. Notice on Newegg they have the typical drives PC/Mac and then those for Mac's specifically. Is there actually any difference, are they physically the same drive? Are the Mac drives just HFS + Journaled pre-formatted ploy to get more money from unsuspecting buyers for the same product? Basically, can any external HDD be formatted for a Mac for reads, writes, and all? And is going for a 7200 rpm drive over the 5400 worth the extra dough?