Trip.com mostly works like a charm for me. My biggest bugaboo about it is that its search interface sucks (generally, I try to use websites that allow me to edit the slug for faster searching). For trip.com, everything has to be manually clicked to confirm (e.g. if I'm flying from Guangzhou to HK, I have to click both a second time). Same with hotels. Inefficient.

I also like how it offers hotel confirmations in two languages.

Diamond users (the highest level) can get two free airport lounge passes (through Dragon Pass). Whaddya know ... it's a QR code. Had to acquiesce there

Anyway, just tried using ctrip (Chinese language). I put in Singapore for hotels ... showed me points of interest with Singapore in the name, but not the location itself. Then, all hotels resulted in "?¥". Sucked.

Have no experience with customer service for the above. But flying in China is still painful. Queuing is still a romp, security is extra sensitive about everything from umbrellas to coins, delays happen without an excuse given, and men's restrooms double as ashtrays. But the flight attendants generally are decent.