We did the 8-day Lemosho route with Monkey Adventures and it was truly an unforgettable experience. We were a group of three, and had three additional "strangers" in our group (who became like family by the end of the week), along with our main guides Charles, Simon and Ola and 19 porters. Every single person from Monkey Adventures was fantastic and put so much care into what they do. They were knowledgeable about the wildlife, the trail and always kept us informed on what to expect the next day. They prepared hot meals for us three times a day, and Monkey Adventurer's tents were great and kept us very warm in even freezing temps.The guides also tested your oxygen levels and heart rate every morning and night to make sure everyone was healthy to continue, which I appreciated since I have an autoimmune and need to be conscious of that.
Another great thing about Charles is how he conducts the summit climb-- he takes special care to bring additional porters on the final climb to make sure there is one guide or porter per trekker in case you need help carrying your pack (or need to be carried down, but all of our group summited). Many of the other groups we saw only had 2-3 guides for their whole group. I ended up getting nauseous due to the altitude on the summit climb and Charles hung back with me the whole time and is the reason I was able to make it to the top.
If you're considering climbing Kili I hands-down recommend it! We chose the 8-day route to leave more time to acclimate to the altitude since we live at sea level typically, and everyone in our group agreed it was the best decision. A few of us got headaches or nausea on the final summit, so we were glad we had the extra day in case our altitude sickness had been even worse. To train, I did 1-2 hour hikes or stadium stair climbs 2-3 times a week with a weighted vest (started at 8 lbs and eventually got up to 22lbs) plus spin class 2 times a week, and I was more than prepared for Kili.
Last thing, don't forget to bring cash in USD (best to have small bills) to tip your porters and guides, they deserve it. Despite any negative reviews of people who are upset that they were not refunded for not summiting, these people take care of you all week-- cooking for you, setting up your tent, carrying your pack if you need help and keeping your safety a priority-- it would be wrong to ask that they are not paid for this work because altitude got the better of you.