I visited China in 2000. Although I usually prefer traveling without being part of a group, this time I went as part of a small guided group (14 people from all over the globe, ages 18 -65).
It was billed as an active tour through Journeys International. Besides seeing the usual sites, they had us doing a bike ride in the countryside, hiking up the mountainsides, lunching with a Chinese farmer's family, etc. Most restaurants we ate at were filled with Chinese people, not Western tourists. We definitely had a different (better, imho) experience than many Americans I've spoken to who only stayed at swanky hotels and ate at touristy restaurants.
Having a guide saved us a lot of time...as we didn't have to worry about transportation (we were on boats (river cruise, ferry, and fishing), trains, planes, mini and full-size buses), accommodations, food, guides, etc.
We ran into a Western couple at a train station who had been trying to get onto a train for 2 days! Without language skills (and no one at the station seemed to speak English) they couldn't seem to get passage out of town.