I want to go back to snow leopard currently on mountain lion, I felt after upgrading its just slowed and my boot time has increased. Basically not performing how it first did. I cleaned what needed to be cleaned I even reinstalled mountain lion whipping my HD just not satisfied. I don't have a external hardrive to transfer stuff but I have enough space to partition my hard rive and make another partition on it for snow leopard and to transfer over my main files, music,pictures, comics and movies at about 150 gb in total. Im thinking of partitioning and installing snow on the second one and once I have everything transferred delete my mountain lion partition and take over the space it was taking up.