I can see myself wanting to try a set of high-powered P/P class-A triode OTL's some day, but I'd have to get the right speakers first...
Do you own the last amp you'll ever buy?
What is the average lenghth of time a component will stay in your system before you upgrade? Are certain components less apt to be replaced than others? Do speakers tend to stay in a system longer than amps or preamps? If you've finally found the Holy Grail, how many years and changes did it take until you found it? Just curious.