I currently have a macbook pro 15" (unibody) looking to downsize a bit. I like all the programs and such and i have a lot of files on my hard drive. If i bought a new computer could i trade hard drives and it will basically be all the same stuff as my old comp or is it more complicated than that? I can put the new hard drive in my current mbp and it will be ready for sale? Also which computers will the 15" MBP (unibody) hard drive fit into? Im looking at 13" MBP or newest macbook. Im just looking to avoid the mess of transferring computers Thanks.