I don't have the 20/20 anymore, but I've owned three over the years. They are very reliable, and work great. I did the 'deep mod' which helps reduce the huge mid hump at higher volumes and brings out a little more bass. It's very easy to do and sounds awesome. I made the mod switchable on one of them so that I could go back and forth as well.
They are nice amps, cheap to re tube, small and light!