Two better than one?

The part of the episode entitled The Replacement, a tale in which Xander gains a doppelganger, that I found to be most interesting was when Xander comments that his doppelganger, not an evil one, but rather a more motivated copy, accomplishes many of the things that Xander himself wishes he was capable of. This is the first time that I have seen a sort of “good” doppelganger appear in literature, TV, etc. and I found the conflicts that such a being presents to be fascinating to examine. What if each of us had another body that was indistinguishable from ourselves that went around doing all the things we wish we were bold enough to do? Would we be happy to sit idly and accept the credit for the actions of our doppelganger? Would we be motivated to go out and do these things ourselves, now equipped with the knowledge that some part of our being was capable of accomplishing these things? These are questions that I certainly don’t have an answer to, but ones that I found arose in both The Replacement and Dr. Jekyll and Mr. Hyde. In Stevenson’s novel, we see the brutal downside of unleashing an unrestricted and ambitious version of oneself, but in Buffy, Xander’s doppelganger does not go down this violent path, begging the question: are two better than one?