Hello all, My name is Joe, I'm brand new to this forum n not as experienced as most of you with computers so please bare with me. I just purchased a part No. MC374LL/A off a friend and im looking to upgrade the drive because im sure the 250gb thats in there wont be enough over time. after doing some searching online i realized youre able to swap out the opti drive. I figure if im purchasing a drive maybe i should go this route with a SSD to make the machine run faster cause if the operating system n heavy work software is on the SSD the 250 thats already in here will be enough for storage. so i guess what im asking for is some advice on what SSD drive I should buy? i have the computer for 1 day n after DL'ing work software its already using like 70gb of my 250... which bay should hold which drive? i read somewhere about a sensor that you might want to leave the HD drive where it is n put the ssd in the opti drive location. which caddy? any advice or opinions will be appreciated. thank you.