Hey- so I stumbled upon this and couldn't believe it! Because I actually work at that company currently. CZZChina isn't bad, and the reason they don't give Z visas right away is because they're a small company. However the owner is a Chinese man with American education, and the office has 2 foreigners working in the office- one as a recruiter and the other as an HR liaison between the foreigners and Chinese staff. I think that's far beyond the business model of most Chinese ESL companies, and I would rather be working at CZZ that many other places I have found in China!

Here is the website, which you can also find by just Googling "CZZChina" (where you can also find a link to their Facebook page).
www.czzchina.com