I've been using beryl for a bit but I'm not sure I'm getting the best out of it - it didn't take me much work to install, so I haven't read that much about it's functions.
So far, the only effects I've found actually useful are the Scale Effect and the Zoom In ... but not in it's favour are the facts that my machine is notably slower when scrolling, the Adept Notifier app no longer lives in the system tray - instead it's taking up valuable room in the normal taskbar and the snap-to feature so that windows align themselves with the corner of the screen seems to have gone.
At some point I'll spend some time trying to work the kinks out ... the two useful effects are actually incredible useful so I'd like to keep them, if I can.
Peter.