I took tests in both Beijing and Guangzhou last year. Both locations are semi-dedicated testing facilities that also host TOEFL tests, and both places offered bag holding service. For me the testing center is a typical Chinese university classroom, with a chair and a desk large enough to pen out the testing book and the answer sheet with room to spare for pencils and erasers. I personally liked the Guangzhou testing room better, as it was brighter and the room had larger individual tables and movable chairs. Testing rooms were not as good as some US classrooms but much better than a chair with an flipping desk as commonly seen in a US college classroom. Guangzhou testing location, if it hadn't changed, is located on the northern edge of downtown, tucked away under Mt. Baiyun. Good* accommodation options are limited. Beijing testing location, if it hadn't changed, is located near the E 4th ring, with an abundance of good* accommodation options. Personally, I took a 40min car ride to the testing center in Guangzhou, and I walked 30min to the testing center in Beijing, both options didn't significantly exhaust me. In my experience, proctors at both testing locations were not as experienced/professional as those in the US. In Beijing I was sitting in the front row and I had to signal the proctor to stop talking as loudly as they were to not distract me from the test, although it might be an isolated incident.

I hope this helps~