I think the obsession with accuracy is actually a bad thing. The author glosses over it, but many games are improved by having slightly higher clock speeds. Game breaking bugs are usually only a problem on lower end games where the devs were doing something hacky.

Personally I always found it frustrating when new versions of MAME would make games unplayably slow on my system in the name of accuracy.

The really important question is are we trying to preserve the games or the hardware? If we're trying to preserve the games than fast emulation with special case hacks for games that need them seems like the way to go. There were a limited number of games released for each system so accurate emulation is just a waste of time.