I LOVE LOVE LOVE this show. I've been an active follower since 2010-ish. I've watched seasons 1-7 a million times.
Now - I finally have watched all the last couple of seasons just in time for season 11 (which is rumored to be the final season...who knows they said that about season 10 too). I was delaying watching season 10, because I wasn't a huge fan of season 8 and 9.
Spoiler, no spoiler, Archer is in a coma and we are watching his mind create some fun scenarios.
Season 8 is dreamland. The gang is back in time and Archer is a detective looking for the one who murdered his partner. Which was okay. I loved the shake-up of the roles of everyone. Some are baddies. Some are goodies. Some have switched genders like Pam.
Season 9 is Danger Island. They are on an island claimed by the French and are on the look of a special artifact. Again, a shake-up of the characters and their roles. No gender flip-flopping, but one of our characters is a talking parrot. Love it. I liked this one a little more than season 8.
Season 10 is 1999. They are space adventurers. The roles have gone back to normal, except Pam is an alien and Kreger is a robot man. I LOVED this season more than the past ones which is funny because it is space-y and more fantasy than the other two. The other two are more historical. Very funny this is my favorite of the seasons that took a side adventure from our normal timeline.
Overall, season 8 and 9. Just okay. Season 10 was fantastic! I actually want to rewatch it now! I cannot wait for season 11. We should be getting back to our normal timeline. I'll give these 3 seasons, a 3.