I'm not the fittest person around - I don't exercise much and I have chronic pain problems - so I found this climb to be rather challenging! It was 6 km and took me about 2h40m to complete. There were a lot of steep stairs and a couple of slopes I thought I couldn't manage but at the end of it I felt a great sense of satisfaction because it was like accomplishing a feat I never knew I was capable of.
We went during China's Golden Week, and because of forecasted traffic jams our meet-up time was changed, an hour earlier than usual. (Mine was the Zhangzizhonglu Subway Station.) Our guide Iris was really knowledgeable about the site, telling us about the history of the Wall before we alighted, and a little bit after we visited the site proper. We had a toilet break on the way there and another one before entering the gates to the Wall; Iris advised those of us who didn't bring food to buy some at the shops at the service area we took our first toilet break at.
The ride was smooth despite the holiday crowds and the driver seemed quite careful. There were seatbelts on every seat and the coach was generally very comfortable.
We arrived around 9 or so and made our way to the Jinshanling Tourist Centre. The toilet here was really clean! After this toilet break we made our way to a little tram stop where we waited for tram (like those you see in Disneyland or certain zoos) to bring us to the actual entrance of the Wall. (It's a huge site.)
Iris gave us a quick briefing and explained the route to us. She asked if anyone wanted to ride the cable car, which would save about an hour's worth of walking; it'd take us to the unrestored part of the wall and she could help us get tickets. (Everyone seemed to want to climb, though after we started walking I think a couple went to ride the cable car; they must've gotten tickets themselves.) She then accompanied us for the first 2 km, I think, then left to meet us at the other side. This first 2 km consisted of the part of the Wall that was restored in the 1980s, I think. The other part was last restored in the Ming Dynasty.
One thing I really liked about this section of the Great Wall was how you could get really good photo ops without anyone majorly photobombing your picture. (It makes sense, because Jinshanling is NOT easy to climb.) We went during peak travel season - Oct 2, the second day of Golden Week - and despite that there were many points during our climb that we found ourselves the only ones on our bit of the wall. That was great.
At certain points there were official personnel stationed around, making sure we knew how to keep to the main route, and at many of the towers/passes there were bazaar-style stalls selling drinks, snacks and souvenirs.
I'd say that we certainly went in the right direction - Jinshanling to Simatai West involved a lot of upwards navigation of tricky areas restored most recently in the Ming Dynasty (according to Iris that's when the Renaissance Period took place, so it's like >500 years old), but at least you're defying gravity so you don't feel like you're in danger. There were some parts that I found it pretty hard to find my footing, and I couldn't imagine going DOWN them - that would be a nasty fall waiting to happen. We also went during a beautiful day, but if it had been raining or snowing, it would've been a really difficult hike. I wouldn't recommend this section of the wall to anyone who is travelling with young children or the elderly - I made it to the meeting point with about 30 minutes to spare, and even then I had to consciously push myself to keep going at the easier parts so I could (a) take my time to climb the tough parts and (b) rest for as long as I could every 20 minutes or so.
All in all I would rate the service itself a 5 out of 5 for the transport, the planning (including the decision to move the meet-up time forward in view of the holiday) and the guide. I do wish I stopped to read more of the history written on the plaques at every watchtower, but I was too afraid of not making the meet-up time, so if you're as unfit as I am, you might want to consider taking the cable car.