So I am just back from Peru. I'm not planning a formal trip report or anything like that, but I will share a couple of comments.
We did travel with only 11 guests, and we still had two guides, Zoe and Rudy, who were awesome. Of our eleven, nine were repeat guests. We loved the small group! The trip overall was great as you would expect. I did want to share a couple of unique points that may be of use to others (or maybe these things only happen to me!)
If your transfer to the Lima airport is only 3.5 hours from your departure time, ask the guides if it can be moved up. Our flight left at 10:05pm, and we were picked up at the JW Marriott at 6:30pm. Given the extreme traffic in Lima, we did not arrive at the airport until 8:00pm and then still had to wait in a long line to check bags and get through security. We made it, but we were near the cutoff for the luggage. Leaving at 6:00, if not 5:30, would have saved a lot of stress. For what it's worth, the airlines recommend you arrive at Lima 3 hours before departure.
When you complete your customs form returning to the US, be very careful about how you answer the question as to whether you've spent time close to livestock. Based on the visit to the Awana Kancha camelid center, I answered yes (as we had in fact been close to, fed, and petted, llamas and alpacas). This was not the answer that the customs folks wanted to hear. We had our passports temporarily seized and had to go through a couple of extra rounds of screening, and then had to have our shoes "sanitized" before we were cleared and got our passports back. So, while I wouldn't advocate lying on the customs form, you should be aware that if you answer that question in the affirmative, you may have a less-than-enjoyable customs experience. Honestly, I figured my answer would be pretty common for people coming from Peru, but the first customs guy looked at me like I had three heads when I said I petted a llama. He said "Oh...you shouldn't have done that" which at first I thought was a joke, but quickly learned was not. Anyway, just thought some might be interested in that experience.