OK...after mulling it around for a few weeks, I decided to just do it. Originally I was just going to go with a 128GB size, but decided that's a little too cramped. So....been agonizing over the different options. I have late 08 unibody so I'm sata2. So the prices are within a few bucks of either going with a single 256GB or 2 128GB drives. I was just about to click the order button with 2 drives and thought I'd check here first for a little validation, lol. Based mostly on user info gleaned through various searches (many here) I was going to get the Samsung 470. But I now see that the Crucial M4 is just a couple bucks more......not sure though cause I read some stuff on owc about how the sata3 drives don't always work so well from the superdrive bay. It seems like the Samsung's will work for sure.