gnome-shell memory leak -It appears there is a memory leak in gnome-shell which is the main window management process. If you stay logged in for a long time and open lots of windows, you may notice things getting sluggish. The most noticeable symptom is probably that you will see a significant delay when locking and unlocking the screen. When this happens the simple fix is to just log out and back in again. An alternate fix that might work is to restart the window manager which you can do with Alt-F2 and then entering 'r' to restart. If that doesn't help, you can restart gnome-shell entirely from the command line by running "gnome-shell -r &".
- Missing acroread - The Adobe acroread application for viewing pdf files is no longer supported on linux. You can use the default Document Viewer application (evince) to view pdf files.
- Missing flash plugin support - Adobe has also discontinued support for the flash plugin for linux so you will not have current flash support if you use firefox. However, google chrome has native flash support so you can run google-chrome.