More adults because it would of course be nice to have someone to hang out with after training etc.
But I would like to go to a serious camp specially if it's only 2-3 weeks. So train from morning to evening with a lunchbreak and maybe 1 day off per week if even that.
My first thought was going for 2 weeks and then maybe take a week vacation in SE asia after.
If you go to a proper base, then it is more kids/juniors
I think what may suite you more in the university team at Da Lian that is open to foreigners too
After training - you can go out drinking with your new friends
You can't do that to the kids in Zheng Ding, unless you make friends with the coaches
If I recall (I organised one of my players to go), Da Lian was USD60 a day, training/accommodation/meal, Zheng Ding has a wide price gap, I also got USD60, but I think most people pay USD70.
The longer stays does allow discounts
You can do your siteseeing at any base if it is 1 day a week
I guess you will be sleeping in the whole morning, so it will be half day siteseeing
Just make sure you train 20+ hours a week for few weeks before going there, else you will be wasting your time recovering from muscle pain
I wanted to organise a "holiday/TT" tour in Tainan (Taiwan) before
A bunch of adults going to train as well as tour/siteseeing
One of my friends - formal top international - Wu Wen Jia has a new base there, some of Chinese Taipei top juniors and some current senior members are there too (when they are not on training duty at the national base which is 1 hour drive away)
Taiwan provides an easy siteseeing attraction compared to China, as China is just way too big to travel to another city
IE Tainan to Taipei is only 1.5 hour by bullet train
Another option is Chuan Chih Yuan's base - Chih Yuan table tennis centre in Kaoshiung, it is run by his brother.
This base in 20 mins away from the national training center
If you are there while i'm there, I can even take you into the national training centre, but otherwise it is not really open to public.