The episodes "Kasas" and "Terra Firma" both ended up becoming the name of two of the more popular Farscape fan forums around. Kansas shut down a while back due to some issues, but Terra Firma is still up and running. Ironically enough, there's a fairly recent discussion that went on about both episodes with favorable opinions of them.
Exactly. He got sucked down a wormhole that happened to lead to Earth in "Unrealized Reality", only actually landed in the next episode because he discovered he'd arrived in the past and was afraid he may have altered the future by doing so (and he had, so he tried to fix it) and by the time he made it back to present-day, Moya had already been spotted and boarded by several humans, including his own father. Crichton even admits that going to Earth was an accident, and it doesn't seem like he spends more than a few days there.
As for the reputation of the episode, it's always been my understanding that it is well liked. My friends and I appreciate it, and on this website
it is ranked 17th out of 90 for the whole series, and that's pretty damn high. This review
also seems quite positive on the whole.
Dissenting opinions are welcome, of course, but I'm not seeing how they are the consensus here.
The episode also has a 9.6/10 with 194 reviews on TV.com. I also thought it was pretty good.