I hesitated a long time, and it was probably better to wait for 10.6.1. Yesterday I ventured's, and after an hour it was all over. Have the Schneeleo over 10.5 drüberinstallier, and - everything works yet, no data was lost, Time Machine data accessible as before, and the computer is faster than ever. My Device: iMac 24 inch, Intel Core 2 Duo, NVIDIA GeForce 9400 graphics card, printer Canon Pixma iP 4600, Time Machine on Western Digital hard disk (communication with the computer better than before!). Had really afraid of this operation, but am now glad that I have ventured's. The beautiful snow leopard photo was also there, which now serves as a desktop background.