Thanks everyone for the help!

Although we'd love to stay longer in Guilin, we have family and people to meet in Hong Kong starting Monday morning (we already pushed our Hong Kong arrival back from Sat night)... As for alternative routes to Hong Kong, I wouldn't mind at all going to Guangzhou or Shenzhen, but my wife vetoed both since we're traveling with our three kids and she felt that a late night arrival and an early morning departure was pushing it a little too far...

We were able to snag the UO flight (thanks Peter!) which really wasn't bad that in terms of price - especially since it allows us to spend 1 1/2 days in Guilin (our good fortune - the price dropped pretty dramatically during the past couple of days while we were trying to make a decision!).

We booked the new Shangri-La in Guilin taking advantage of some very reasonable grand opening rates that include breakfast and internet access (the rooms alone were cheaper than the Sheraton) - not to mention the fact that the Shangri-La's pools look really nice!

As for a Li River cruise that allowed us to make our 6pm flight, we looked at two options, taking the regular boat and getting off at Xingping then taking a direct private car to the airport OR taking a private boat (shorter time on the river), spending a couple of hours or so in Yangshou, then taking a private car to the airport. This was actually a really tough decision as we very much enjoyed our last leisurely Li River Cruise ten years ago... Both were fairly comparable in cost and we opted for the later so that we could spend some time in Yangshou.

It felt like the best option give our time and family dynamic constraints, but feel free to weigh in!

Thanks everyone for your help and insights - it really makes this trip a lot easier!