Avalon is the first in a trilogy of episodes that set up not only the season the come but the direction of the show for the next two seasons and probably the two movies to follow. In many ways, and it's not easy for me to admit this, it really is a new show. Jack is nowhere to be seen, Sam barely has a cameo, Teal'c has moved on, and Daniel is trying to do the same. The SGC has a new leader in General Landry, a bit of a hardass, a new leader for SG-1 with Colonel Mitchell, and even a new doctor. The new cast members (along with Daniel's beard) certainly give the show a different feel, a point hammered home with the return of one-time guest star Vala Mal Doran. I will admit that with Vala I'm a bit biased being a huge Claudia Black fan and getting to see her in a role that's so different from any I've viewed before. Vala brings an entirely new and in my opinion fun energy to the team and the show in general. Her chemistry and interaction with Daniel are fantastic and lead to some of the best moments in the episode. She also provides the means for the beginning of the show's next story arc and works as a sufficient stand in for Carter's absence early in the year. With the Goa'uld all but eliminated and the Replicators wiped out, we get an entirely new story. Keeping in the theme of alien races inspiring Earth mythology, Daniel discovers that the Merlin the wizard of King Arthur fame was an Ancient and our new story is begun. Personally, I find the fact of Merlin being an Ancient to be fascinating so I enjoy that part of the storyline. Other high points in the episode involve Mitchell's fruitless attempts to bring the old SG-1 back together and his even more frustrating attempts to recruit new members. The end of the episode brings about a new adventure, another cave, and lots of good ol' fashioned peril.
The episode's not without its flaws, though. The scenes involving the Free Jaffa and the rise of the ambitious Gerak aren't all that interesting, though having Lou Gossett Jr. on the show is kind of fun. The episode overall gets off to a pretty slow start until they board the Prometheus toward the end. Understandable for an episode that is in essence a reboot for the series. It takes a little while to set something like that up. In the end, a solid start to a new season and new team.