I Have only had one issue with lion, which a disk/permissions repair resolved. Looking at 6 other people I have suggested a clean install to, all of them have had their quirks resolved and their machines are running fantastic. These are machines from early 2008 macbook pro on up to current machines. I attribute this all to clean installs. Folks need to understand that directory corruption, and other software issues can create havoc on a system and upgrading an OS is rarely a great a idea. I'm sure there are some driver issues for specific people that are at the OS level, but give a clean install a shot!