I guess, I'm a bit divided on this. While software is abstract (and deterministic), the experience of running the software is not. Meaning, as you become part of a feedback loop, the sensorical side of things matters. And this is really hard to recreate.
E.g., not only do emulators introduce lag, also modern systems tend to be laggier than vintage ones. Graphics taylored to the specific attributes of a display technology won't convey the original feeling on modern hardware. Or, interacting with a game using modern controllers, by D-pad or thumb stick, which are operated by fine motor control, feels much different from using joysticks that involve the entire body, by this establishing a rhythm. (This is also true the other way round, e.g., Pong, meant to be controlled by fine motor controls using a paddle, is half the fun using the brute means of a digital joystick, either jammed up or down.)
This may sum up to the effect of the user entirely missing the point of a game. (There are some VCS games, I always deemed to be noteworthy, which are generally rated low in modern reviews. I had a hard time understanding why reviewers would miss the rather obvious qualities of those games – until I tried them using a D-pad controller.)
P.S.: This doesn't mean that emulators aren't worth it (to the contrary, it's great to have them), but it may be worth keeping in mind that you are not necessarily having the original experience.
E.g., not only do emulators introduce lag, also modern systems tend to be laggier than vintage ones. Graphics taylored to the specific attributes of a display technology won't convey the original feeling on modern hardware. Or, interacting with a game using modern controllers, by D-pad or thumb stick, which are operated by fine motor control, feels much different from using joysticks that involve the entire body, by this establishing a rhythm. (This is also true the other way round, e.g., Pong, meant to be controlled by fine motor controls using a paddle, is half the fun using the brute means of a digital joystick, either jammed up or down.)
This may sum up to the effect of the user entirely missing the point of a game. (There are some VCS games, I always deemed to be noteworthy, which are generally rated low in modern reviews. I had a hard time understanding why reviewers would miss the rather obvious qualities of those games – until I tried them using a D-pad controller.)
P.S.: This doesn't mean that emulators aren't worth it (to the contrary, it's great to have them), but it may be worth keeping in mind that you are not necessarily having the original experience.