Exit size doesn't matter on its own - you have to take into account how much equity you own. 40% of $100 million exit is better than 10% of $300 million - as an example. I would describe the first scenario as more successful than the second.
I am taking this from the founder's point of view, where no money is paid to buy the equity. You highlight the good point that it depends on the context and point of view - who's success is being talked about.
