The most scenic ride I had in China was a bus ride from Shangria-La to Lijiang.The road scary in spring, in winter would be worst.In Xishuangbanna you can take a raft trip down the Mekong river.I would recommend a show.There are a couple shows.The GREEN brochure has a great show. You can skip the dinner but show is very good for entertainment would recommend that you stay in old town in both Dali and Lijiang.
Flew to Xishuangbanna so I can not tell you about the scenery as you drive