There are two things I don't like about that stanza. First: duh. If two roads diverge, taking one instead of the other will make all the difference. If I'm at the crossroads of I-70 and I-95 in Baltimore, and I take I-70, I will never reach Miami or Boston or New York. But if I take I-95, I will never hit Indianapolis or St. Louis Kansas City or Denver. Those are completely different experiences, and those differences result from taking a different road.*
*You may be interested to note that I-70 is probably less traveled by than I-95.
Second, the rhythm gets awkward. The words "hence" and "difference" are only imperfect rhymes. Poetry, for me at least, is all about rhythm and sound. That last line is something like the last note of a song being slightly sharp. Your ear picks it up, even if your conscious mind doesn't. I don't like it.
That said, I like the poem. It's one of two I (currently) have committed to memory. The poem has an interesting irony to it. He claims to have taken the road less traveled by, but says that "both that morning equally lay in leaves no step had trodden black." The first stage of the irony is the "equally" part: neither road was particularly less traveled than the other. The second stage is the "no step had trodden black" part: both roads were pretty untraveled. So, really, he didn't take the road less traveled, at least among the two that diverged in the yellow wood. Is he lying to himself?
But then there's the other part, the growing up part, the part about how "way leads on to way" and the slow realization that living involves making choices and regretting them and wondering what might have been and realizing the full depth of not being able to go back. If I could go back, would I try out for football in seventh grade? Would I sign up for band in sixth grade? Would I choose Howard Payne over Mary Hardin-Baylor again? Or Baylor over Texas? Would I still major in political science instead of chemistry? Would I buy this car again or that phone? Would I try harder in calculus?
When I was 16, Hewitt Drive was a well-traveled road. When you hit Spring Valley Road, you could turn right or left. Left was more well-traveled than right. If you went right, you would eventually hit Old Lorena Road, which was a little more traveled than Spring Valley Road. But if you kept going, you would hit Cotton Belt Parkway, less traveled than Old Lorena, Spring Valley, or Hewitt Drive. Cotton Belt Parkway would take you to Church Road. Church Road, at the time, was so untraveled that it had a one-lane wooden bridge. And Church Road would take you to those unnamed county roads.
Maybe Frost started off on Hewitt Drive but ended up on County Road 314.