Thanks everyone for your suggestions. I'm still deciding on the details of our itinerary, but your postings have helped provide us with more info. Thanks again!

We are doing a similar trip but in reverse order. We're going in April, flying in and out of Hong Kong. We arrive at 6pm Monday after a 15 hour + flight and will have a day to acclimate and see our daughter in Shenzhen. Planning to fly out Tuesday night to Guilin and have car pick us up at the airport to take us to Yangshuo. Spend two days (maybe three) in Yangshuo and then go to rice terraces on Friday day trip and leave from Guilin via plane to Xian. Arrive in Xian at night spend day and night (Sat and Sunday) Xian and take sleeper train to Beijing Sunday night. Spend three days in Bejing then fly to Shenzhen late at night (Thursday) or early in the morning (Friday). Spend rest of day in Shenzhen and last day in Hong Kong. Fly home on Sunday.

I thought it would be excellent to start off in Guilin to kind of kick back and do a cooking class, walk around a bit before hitting the big cities. Well, I guess we'll do that right off with Hong Kong and Shenzhen but there's no way to get around that and my daughter said something about a very cool spa in Shenzhen that might be really nice.