... the upgrade from Lion to Mountain Lion was completely problem free.
The longer you put it off, the more changes there will be and the steeper the learning curve you will have to climb.
I believe that for both tacit and Artie the issue here was/is the upgrade from Snow Leopard rather than from Lion. Mac OS X' change to (a.o.) the iOS feature set started with Lion, and once you're used to that the move to Mountain Lion would be decidedly less jarring.
But you're right that the 'culture shock' of moving beyond Snowy will only increase in severity with each new version of Mac OS X. Apart from that I
know that the actual upgrade process itself will be smooth for me (a notorious
late adopter), because I'll get it pre-installed with the new Mac I'm (eventually) going to get.
