We took a full day tour of Lima, and I strongly recommend it. While on the
ABD trip, you really don't formally do or see much in Lima except the one grand private home meal.
Our ABD guides hooked us up with a fantastic local guide, who was with us for the day. It was the best investment we made on the whole trip. We had a 20 year old son, and 9 year old twin girls - and they loved it. The ABD guides negotiated the rates for us, and the rate included the entrance fees to everything. We toured a monastery, several Cathedrals, the catacombs, plazas and parks, visited the ruins at Hauca Pucliana (from 400 AD). It was a walking and taxi driven tour that left us breathless with awe, and held the attention of both my girls and son. We were also directed to simply fantastic places to eat. We did explore some on our own, and that did not work out to be too productive.
The people in Lima are generally friendly, helpful, and grateful for you to spend your money. Our Disney provided escort from the airport to the hotel at the start of our trip was a disaster. He picked us up, drove us to Lima, left us at the wrong hotel and took off. We did not speak Spanish, and the deposited hotel did not have anyone speaking English. Fortunately, several locals in the lobby came to the rescue, flagged us a cab, told us in broken English where we needed to go and off we went. However, we had about three very uncomfortable hours trying to work this out on our own. The Disney "emergency number?" It's long distance - and no one would let us use their phone. It was an expensive cab ride, by the way. Disney didn't seem to think this was much of an issue though.
We have developed a real love of things Peruvian now, and just last week went to see the "Inca Son" live in concert - because we all miss the pan flutes and music.
There were some "problems" on our tour. (Road closures, etc.) Disney covered them okay - I was grateful for being a part of an established tour group. On the other hand, we missed several of the things I really wanted to do. I say this to encourage you to take advantage while you can of things. While in Cusco, we visited museums, etc. way off the Disney grid. (Most museums are open until 10-11 pm - we had our own spooky night at the museum). While at Sol y Luna, take a horseback ride, jump into the spa. The hotel told us we were the first in a year to take a horseback ride from the Disney group. It was amazing. Disney does a good job on the planned tour - but its limited.
Enjoy!