Just watched this episode. Another good one. I think this season will end up being my favorite since S3, honestly. The humor is just hitting the mark with me.
S4, S5, and S6 are kind of a blur to me. I can't remember if I liked any of them. Either I liked S4 and didn't like the other two, or I didn't like S4 and S5 but liked S6. I definitely remember two seasons worth of the show being merely watchable (as opposed to being one of my top shows, like it was in S1-S3).
Whenever the Avery plotline began is basically when the show took a bit of a dip for me. I just can't remember when things picked up. S7 has been rocking it so far though so at least I know that.
EDIT: Okay, so I just searched my old posts in the 30 Rock Season Six thread and apparently I did prefer that season to the previous two. I really think that Elizabeth Banks being on the show marked its weakest points in S4-S5, at least in my own opinion. I never cared for Avery but it was more than just her character that brought the show down during S4-S5, so I guess it was merely a coincidence that I can say the "Avery period of the show" was the worst.
So it's looking like S1=S2>S3=S7>S6>S4=S5, and that's with S7 being incomplete. I really enjoy that the final season of a show is capable of being one of its best. You don't often see that.