I'd studied Chinese online for a few years, very slowly, but the four weeks I spent at the CLI in Guilin were an amazing boost to my progress, and a wonderful experience!
Support:
The admin support was top-notch; I had some minor issues in getting my visa and when I arrived, and both the admin staff and the student intern who met me on day one (and, later, helped me navigate the many apps!) were warm, supportive, and incredibly helpful. The airport pick-up and drop-off were highly appreciated and seamless.
Classes:
My three teachers were all encouraging, enthusiatic, and dedicated to my progress. They figured out where my weak points were and worked on a plan to address them with me, while shoring up my strengths. My Chinese improved dramatically over the four weeks I studied with them. After a couple weeks, I was having slow conversations with taxi drivers, long chats with people in shops, and waking up thinking in Chinese! My reading speed also advanced a lot. I did spend a fair amount of time outside of class as well reviewing the vocab and grammer, so I'd say if you're prepared to work hard you can really accelerate your progress in a very short time.
Activities:
I did a lot of activities offered through the school, and really enjoyed the option to try them out. I think especially as someone who was only there for a couple weeks, it's hard work to find and plan your own activities, and I enjoyed the school's. I got to see some beautiful scenery (trips out to Yangshuo were great!), eat a lot of amazing meals, and learn a little bit about a variety of things: music, dance, calligraphy, and more. (Also the school lunches are delicious.) The CLI is in a non-touristy part of Guilin but near loads of shops, markets, restaurants, etc., so it's very easy to get around even while you're still figuring things out. I really liked the neighbourhood vibe.
Overall:
I'm very glad I went, and would go again in a heartbeat. Highly recommend.