Is it fair to compare US presidents?

Tweet

For example Obama may have an easy 8 years free of relative unrest. Bush had the unfortunate events on 9/11, Katrina etc on his plate. Is it fair to say that a president is going to be remembered highly if his 4-8 year reign is realtively event free? I mean how many world changing things happened in 1992-2000 vs 2000-2008? It's unfair to compare as certain 8 year periods may have been harsher than others in terms of descisions that had to be made.